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FiscHER, P.-H., DuvAL, M. & Rarry, A. 1933. Etudes sur les échanges respiratoires des littorines. Archs

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Konn, A. J. 1960a. Ecological notes on Conus (Mollusca: Gastropoda) in the Trincomalee region of Ceylon.

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ANNALS OF THE

SOUTH AFRICAN MUSEUM

VOLUME 80

ANNALS OF THE SOUTH AFRICAN MUSEUM

ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM

Volume 80 Band

August 1980 Augustus

CRETACEOUS FAUNAS FROM ZULULAND

AND NATAL, SOUTH AFRICA

THE AMMONITE SUBFAMILY TEXANITINAE

COLLIGNON, 1948

HERBERT CHRISTIAN KLINGER

WILLIAM JAMES KENNEDY

Cape Town Kaapstad

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CRETACEOUS FAUNAS FROM ZULULAND AND NATAL,

SOUTH AFRICA

THE AMMONITE SUBFAMILY TEXANITINAE COLLIGNON, 1948

HERBERT CHRISTIAN KLINGER

South African Museum, Cape Town

| WILLIAM JAMES KENNEDY

Geological Collections, University Museum, Oxford

(With 269 figures)

[MS. accepted 14 September 1979]

ABSTRACT

Ammonites referred to the subfamily Texanitinae Collignon, 1948, are the dominant

macrofaunal element in rocks of Upper Coniacian to Middle Campanian age in Zululand,

Natal, and Pondoland, and are of extreme interest as far as intraspecific variation, evolutionary

trends, apparent endemism and gigantism are concerned. The subfamily is represented by

thirty-seven species belonging to the following genera and subgenera: Protexanites s.s., Para-

texanites, Plesiotexanites, Reginaites, Texanites, Submortoniceras, Bevahites, Menabites s.s.,

M. (Australiella) and M. (Delawarella). Subtle differences exist between the Pondoland and

Zululand specimens, and these are here separated at subspecific level. Thirteen new species

and three new subspecies are described; these are—new species: Paratexanites australis,

P. pseudotricarinatum, Plesiotexanites collignoniforme, P. matsumotoi, Reginaites reymenti,

R. zulu, Texanites collignoni, T. vanhoepeni, T. postvanhoepeni, T. umzambiense, Bevahites ?

enigma, Menabites (Delawarella) gigas, M. (Delawarella) nibelae; new subspecies: Texanites

presoutoni presoutoni, T. presoutoni natalense, T. soutoni natalense; and Reginaites? sp. nov.?

cf. Plesiotexanites stangeri (Baily).

Evolutionary trends are discussed within the Texanitinae as shown by the South African

faunas. The geographic distribution of the subfamily shows it to be highly endemic and prolific

towards the end of the Santonian and during the Lower and Middle Campanian, shortly

before its demise.

CONTENTS

Introduction 1

Location of specimens 3

Field localities : ; : 3

Dimensions of specimens - i : : : ; 4 3

Suture terminology 3

Annotation of Grime nation 3

Systematic palaeontology : : 4

Evolution and evolutionary frends in Texanitinae . 348

Palaeobiogeography . : : : ; : : . 350

Acknowledgements . ; : : ‘ : ' yee DS)

References . : : : : ; : : ; 5 254s

INTRODUCTION

Ammonites referred to the subfamily Texanitinae Collignon, 1948, are

the dominant macrofaunal element in the Upper Coniacian to Middle Cam-

panian sediments of southern Africa, both in terms of numbers of individuals

Ann. S. Afr. Mus. 80, 1980: 1-357, 269 figs.

2 ANNALS OF THE SOUTH AFRICAN MUSEUM

and species, and are of extreme interest as far as intraspecific variation, evolu-

tionary trends, apparent endemism and gigantic growth are concerned. Further-

more, identification of these faunas allows for detailed stratigraphic correlation

with biostratigraphically equivalent strata of Madagascar, and to a very limited

extent those of western Europe, the Gulf Coast regions of North America, and

Hokkaido, Japan.

The authors were struck by the bewildering array of intraspecific variation

in the texanitine material at their disposal. Features such as density of ribbing

and tuberculation, presence or absence of bifurcations or intercalations, and

even relative proportions, which, by current ammonoid classification standards,

would be of specific or even generic value, were found to be of relatively minor

taxonomic significance if viewed in their proper stratigraphic context. This does

not imply that the authors negate the possibility of more than one species being

found at the same stratigraphic level, but rather emphasizes that specific identity

should be viewed in terms of consanguinity of characters rather than typo-

logically. In this respect, the authors were hampered somewhat because a large

proportion of the available material is from older collections, primarily that

of the late Dr E. C. N. van Hoepen, which lack precise stratigraphic data.

Detailed collecting by the authors during several field seasons alleviated this

shortcoming to some degree.

In addition to the extreme intraspecific variation, a biogeographic separa-

tion into a northern Zululand fauna frequenting the deeper water facies of the

St Lucia Formation of the False Bay region, and a southern fauna frequenting

the shallower water of the transgressive Umzamba Formation of Pondoland,

Transkei, becomes apparent.

In identifying the South African material, the authors made extensive

use of the monographical studies of Collignon (1948), and the Santonian and

Campanian parts of his subsequent series Atlas des fossiles caractéristiques de

Madagascar (Ammonites) (1966a, 1969, 1970), Young’s (1963) description of

the Upper Cretaceous faunas of the Gulf Coast of America, and Matsumoto’s

(1970) recent description of the Texanitinae from Hokkaido.

Unfortunately, the majority of texanitine species seems to be endemic,

thus precluding precise stratigraphic correlation on a global scale. Similarities

between the South African and Malagasy material are striking, and Collignon’s

biostratigraphic zonation compiled for Madagascar could be employed to good

effect. This notwithstanding, a great proportion of the material appears to be

new, necessitating the erection of new species.

The association of the form genus Spinaptychus Trauth with representatives

of the subfamily Texanitinae is firmly established on the basis of more material

to supplement previous records by the authors (Klinger 1972, Kennedy &

Klinger 1972).

Broad outlines of the evolution and evolutionary trends within the Texani-

tinae, as displayed by the South African material and aspects of the palaeobio-

geography of the subfamily are discussed after the systematic descriptions.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 3

LOCATION OF SPECIMENS

The following abbreviations are used to indicate the respositories of the

material studied :

BMNH British Museum (Natural History), London.

NMB_ National Museum, Bloemfontein (presently housed in the collections

of the South African Museum, Cape Town).

OLL OberOsterreichisches Landesmuseum, Linz.

SAM South African Museum, Cape Town.

SAS Geological Survey of South Africa, Pretoria.

™ Transvaal Museum, Pretoria.

UN Geology Department, University of Natal, Durban.

FIELD LOCALITIES

Details of field localities referred to in the text are provided in Kennedy &

Klinger (1975). Full descriptions of the localities are housed in the libraries or

collections of the British Museum (Natural History), Geological Survey of

South Africa (Pretoria), and the South African Museum.

DIMENSIONS OF SPECIMENS

Dimensions of specimens are given in millimetres; abbreviations are as

follows:

D = diameter, Wb = whorl breadth, Wh = whorl height, Wb:Wh = ratio

of whorl breadth to whorl height, U = umbilical diameter.

Figures in parentheses are dimensions as a percentage of total diameter.

SUTURE TERMINOLOGY

The suture terminology of Wedekind (1916; see Kullmann & Wiedmann

1970 for a recent review) is followed in the present work:

I = internal lobe, U = umbilical lobe, L = lateral lobe, E = external

lobe.

ANNOTATION OF ORNAMENTATION

Terminology of tuberculation followed here is essentially the same as that

of Collignon (1948: 55), and Young (1963: 37, text-fig. 6), reproduced here in

slightly modified form as Figure 1. Tubercles are numbered sequentially from

the umbilical wall ventrally towards the keel; the umbilical tubercle (Ut) is

number 1, the lateral tubercle (Lt) 2, the submarginal (St) 3, the marginal

(Mt) 4, and the external (Et) 5. This is a genetic annotation. In genera lacking

the lateral tubercle, the second tubercle encountered ventrally from the umbilical

wall is situated submarginally, and thus annotated as number 3. Similarly, in

genera where two or more tubercles arise through division of a single tubercle,

the latter is referred to according to its position, e.g. ventrolateral, with the

ANNALS OF THE SOUTH AFRICAN MUSEUM

Keel

External (5)

Se IE as eres Submarginal (3)

See Lateral (2)

---"

Umbilical (1)

Dorsal zone of impression

Fig. 1. Whorl section of a texanitine ammonite

to explain annotation regarding ornamentation

used in the text; modified after Collignon (1948:

55) and Young (1963: 37, text-fig. 6).

numbers of the tubercles it eventually gives rise to in parentheses, e.g. (3-+4),

Rib-counts are indicated as the number of internal (Int.) (umbilical)

tubercles versus the number of external (Ext.) tubercles. It was found imprac-

ticable to annotate and count ribbing in terms of bifurcating and/or intercalatory

ribs as the distinction between these is often slight and generally of subordinate

importance in texanitine systematics.

SYSTEMATIC PALAEONTOLOGY

Phylum MOLLUSCA

Class CEPHALOPODA

Subclass AMMONOIDEA Zittel, 1884

Superfamily ACANTHOCERATACEAE de Grossouvre, 1894

Family Collignoniceratidae Wright & Wright, 1951

Subfamily Texanitinae Collignon, 1948

The subfamily Texanitinae is a prolific group, ranging in age from ?Lower

Coniacian to Middle Campanian, and is best known from Madagascar, the

Gulf Coast regions of North America, and Hokkaido, Japan. The subfamily

is herein taken to include the following genera and subgenera:

CRETACEOUS FAUNAS FROM SOUTH AFRICA 5

Texanites Spath, 1932

Paratexanites Collignon, 1948

Bevahites Collignon, 1948

Submortoniceras Spath, 1921

Menabites s.s. Collignon, 1948

Menabites (Bererella) Collignon, 1948

Menabites (Delawarella) Collignon, 1948

Menabites (Australiella) Collignon, 1948

Protexanites s.s. Matsumoto, 1955

Protexanites (Miotexanites) Matsumoto, 1970

Protexanites (Anatexanites) Matsumoto, 1970

Protexanites (Pleurotexanites) Matsumoto, 1970

Plesiotexanites Matsumoto, 1970

Reginaites Reyment, 1958

Defordiceras Young, 1963

Obvious synonyms of these taxa are discussed in the text. Initially, the

subfamily Texanitinae formed a relatively homogeneous group, consisting of

unicarinate trituberculate to pentatuberculate taxa, but lately through the

inclusion of Reginaites, P. (Pleurotexanites), and Defordiceras, the definition

has to be modified to accommodate these tricarinate, interrupted unicarinate,

and keel-less forms.

Generic subdivision is based mainly on the number of rows of tubercles.

Protexanites is trituberculate throughout, except in P. (Anatexanites) where

a lateral (2) row of tubercles is added in later stages. Paratexanites is quadri-

tuberculate throughout, lacking the lateral (2) row of tubercles. Texanites is

pentatuberculate from an early stage, as is Submortoniceras, but in the latter,

lateral ornament weakens in later stages of growth. Plesiotexanites links between

Paratexanites and Texanites in forming a lateral tubercle after variable stages

of growth. Bevahites and Menabites s.\. differ from the other genera in having

more tubercles in the external (5) row than in the other rows. In Bevahites the

marginal (3) and submarginal (4) tubercles remain more or less approximated

throughout, thus differing from Menabites. Reginaites is bituberculate to

quadrituberculate, as here interpreted, but is distinctly tricarinate as in Peroni-

ceras. This latter similarity is an example of homoeomorphy and not genetic

affinity. Defordiceras lacks a keel on the outer whorls. Whether this condition

also prevails on the inner whorls is unknown.

The suture throughout is relatively simple with a primary suture formula

ELU,UjI.

The following species are described from South Africa:

Protexanites cycni (van Hoepen)

Paratexanites australis sp. nov.

Paratexanites pseudotricarinatum sp. nov.

Paratexanites umkwelanense (Crick)

6 ANNALS OF THE SOUTH AFRICAN MUSEUM

Paratexanites sp. aff. P. emscheris (Schliiter)

Paratexanites sp. aff. P. serratomarginatus (Redtenbacher)

Plesiotexanites stangeri (Baily)

Plesiotexanites collignoniforme sp. nov.

Plesiotexanites matsumotoi sp. nov.

Plesiotexanites ? sp. indet.

Reginaites reymenti sp. nov.

Reginaites zulu sp. nov.

Reginaites ? sp. nov.? cf. Plesiotexanites stangeri (Baily)

Texanites collignoni sp. nov.

Texanites quadrangulatus Collignon

Texanites vanhoepeni sp. nov.

Texanites postvanhoepeni sp. nov.

Texanites rarecostus Collignon

Texanites texanus (Roemer)

Texanites umzambiense sp. nov.

Texanites presoutoni presoutoni ssp. nov.

Texanites presoutoni natalense ssp. nov.

Texanites soutoni soutoni (Baily)

Texanites soutoni natalense ssp. nov.

Submortoniceras woodsi s.\. (Spath)

Submortoniceras condamyi s.\. (Collignon)

Bevahites ? enigma sp. nov.

Bevahites sp. A. gr. ex. B. subquadratus Collignon

Bevahites sp. B. gr. ex. B. subquadratus Collignon

Menabites (Menabites) boulei Collignon

Menabites s.l. sp. juv. indet.

M. (Australiella) australis (Besairie)

M. (Australiella) falloti (Collignon)

M. (Delawarella) delawarensis (Morton)

M. (Delawarella) subdelawarensis Collignon

M. (Delawarella) sp. aff. M. (D.) jeanneti Collignon

M. (Delawarella) gigas sp. nov.

M. (Delawarella) nibelae sp. nov.

M. (Delawarella) sp. indet.

Genus Protexanites Matsumoto, 1955

Type species

Ammonites bourgeoisi d’Orbigny, 1850, by original designation of Matsu-

moto (1955: 38).

Discussion

The genus Protexanites was originally erected by Matsumoto (1955) for

species ‘similar to Texanites in general aspect . . . typically trituberculate . . .

CRETACEOUS FAUNAS FROM SOUTH AFRICA 7

and sometimes quadrituberculate in the later whorls with one lateral tubercles

[sic] in addition to the other three’ (Matsumoto 1955: 38). Since then, however,

more material has become available and Matsumoto (1970: 227-228) now

recognizes four distinct subgenera:

Protexanites s.s. Matsumoto, 1955 (type species Ammonites bourgeoisi d’Orbigny,

1850).

Anatexanites Matsumoto, 1970 (type species Mortoniceras fukazawai Yabe &

Shimizu, 1925).

Miotexanites Matsumoto, 1970 (type species Protexanites (Miotexanites)

minimus Matsumoto, 1970).

Pleurotexanites Matsumoto, 1970 (type species Protexanites superbus Collignon,

1966a).

Differences between the various subgenera are distinct. Protexanites s.s.

is trituberculate throughout; Anatexanites acquires a lateral (2) tubercle at

varying stages of growth; in Miotexanites the development of the ventrolateral

tubercle is retarded, and in Pleurotexanites the tubercles of the external (5) row

outnumber those of the umbilical (1) or submarginal (3) rows; in addition, the

keel, consisting of a line of multiplied tubercles, is interrupted.

Only representatives of Protexanites s.s. occur in southern Africa, hence

the reader is referred to Matsumoto (1970) for discussions on the limits and

affinities of the other three subgenera. Species referred to these latter subgenera

by Matsumoto (1970) are:

Subgenus Anatexanites

P. (Anatexanites) fukazawai (Yabe & Shimizu) (1925: 130, pl. 30 (fig. 1), pl. 31

(figs 1-2, 6-7, non 3), pl. 33 (figs 1-2)) from the Middle Santonian of Kyushu

and Hokkaido.

P. (Anatexanites) nomii (Yabe & Shimizu) (1925: 131, pl. 32 (figs 1-3)) from the

Santonian of Hokkaido.

P. (Anatexanites) reymenti Matsumoto, 1970 (=Texanites cf. quattuornodosus

in Reyment 1955: 93, pl. 23 (fig. 3), text-fig. 46a) from the Santonian of

southern Cameroons.

Subgenus Miotexanites

Protexanites (Miotexanites) minimus Matsumoto (1970: 246, pl. 33 (figs 1-3),

text fig. 8) from the Coniacian or Lower Santonian of Hokkaido.

? Niceforoceras (?) japonicum Matsumoto (1965: 71, pl. 11 (fig. 1) text-fig. 40)

from Hokkaido may be an example of Miotexanites.

Subgenus Protexanites Matsumoto, 1955

Type species

Ammonites bourgeoisi d’Orbigny, 1850, by the original designation of

Matsumoto (1955: 38).

8 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis

Following the very early smooth stages, ornament consists of single,

bifurcating or intercalatory ribs bearing three rows of tubercles only; umbilical

(1), submarginal (3), and external (5). The keel may be entire or crenulate.

Primary suture quinquelobate with formula ELU,U,I.

Discussion

Matsumoto (1970: 228) referred the following species to Protexanites s.s.:

P. (Protexanites) bontanti (de Grossouvre) (1894: 77, pl. 17 (fig. 2 only)) from

the Coniacian of France.

P. (Protexanites) bourgeoisi (d’Orbigny, 1850) (De Grossouvre 1894: 73, pl. 13

(fig. 2), pl. 14 (figs 2-5)) from the Senonian of France.

P. (Protexanites) canaensis (Gerhardt) (1897: 73, pl. 1 (fig. 2a-c)) from the

Lower Senonian, presumably Coniacian, of Venezuela.

P. (Protexanites) peroni Matsumoto, 1970 (=Peroniceras czoernigi Peron non

Redtenbacher, 1896: 53, pl. 11 (figs 7—-8)) from the base of the Senonian of

Djebel Aures, Algeria.

P. (Protexanites) shoshonense (Meek) (1876: 449, pl. 6 (figs 3a, c, 6b)) from the

Coniacian of Wyoming.

P. (Protexanites) strozzii (Desio) (1920: 204, pl. 12(1) (fig. 8)) from the Senonian

of Florence, Italy.

To this list may be added:

P. (Protexanites) eugnamtus (Redtenbacher) (1873: 117, pl. 27 (fig. la-c)) from

the Coniacian of the Gosau Beds, Austria. (See Reyment 1958: 45.)

Of these species half are either monotypic or poorly known, having been

figured once or twice only. These include P. (P.) canaensis and its variety

obliquecostata, P. (P.) peroni, P. (P.) strozzii and P. (P.) eugnamtus.

Detailed descriptions and figures to illustrate the extensive intraspecific

variation and ontogeny of P. (P.) shoshonense and P. (P.) planatus were provided

by Reeside (1927) and Young (1963) respectively. Illustrations and descriptions

of the types of P. (P.) bourgeoisi and P. (P.) bontanti were provided by Matsu-

moto (1966, 1970). :

As appears to be the case in other regions, Protexanites is poorly repre-

sented in the Coniacian of Zululand, both in numbers and in species. One

species only, P. (P.) cycni (van Hoepen) is described below.

Due to their relative scarcity throughout the world, current systematics

in Protexanites seems to be typologic, rather than based on actual populations,

and is extremely conservative when compared with systematic concepts applied

to Texanites or Submortoniceras. Specific characters in Protexanites include,

apart from relative proportions, density and curvature of ribbing, strength and

position of the umbilical (1) and submarginal (3) tubercle, and whether the keel

is entire or crenulate. Amongst these, possibly only the latter is of real signifi-

cance in Texanites, but it varies according to preservation.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 9

Comments on the phylogeny of Protexanites and Paratexanites are given

on p. 16.

Occurrence

Coniacian to Lower Santonian of western and central Europe (France,

Spain, Italy, Austria, Czechoslovakia, Rumania), Israel and Sinai, North

America (Gulf Coast and Western Interior), South America (Venezuela

and Peru), Japan and Saghalien, north Africa (Algeria), South Africa (Zulu-

land), and Madagascar.

Protexanites (Protexanites) cycni (van Hoepen, 1965)

Figs 2-4

Subprionocyclus cycni van Hoepen 1965b: 183, plate I.

Subprionocyclus cycni? van Hoepen 19655: 183.

Type

Holotype is SAS—Z651 by the original designation of Van Hoepen (1965b:

183), here refigured as Figure 2D-F.

Material

SAS-Z808 and SAS-—Z832, locality 93, near the Hluhluwe Estuary, Zulu-

land, St Lucia Formation, Coniacian II to possibly III, the same locality and

horizon as the holotype; BMNH-C81431-—C81433, locality 91, close by locality

93, St Lucia Formation, Coniacian IV-V.

Dimensions

D Wb Wh Wb: Wh U Int. EXE:

Z651 43,0 13,0(30) 17,0(40) 0,76 14,0(33,0) — —

Z834 62,0 20,0(32,3) 21,5(34,7) 0,93 26,0(41,9) 16 22

Z832 72,0 — 28,0(38,9) — 2S:0C 8:9) en 2 elo <2

Z808 90,0 27,0(30,0) 32,0(35,5) 0,84 BUKUGHEID) DPA ws<ey

Description

This is a relatively small-shelled species, the maximum observed diameter

being 102 mm, of which half is body chamber. The umbilical width varies during

ontogeny, being narrowest in early stages at 33 per cent, to wide in later stages

at 41 per cent. Whorl overlap is negligible. Barring the early, smooth stage, the

whorl section throughout is higher than wide, with maximum width at the

umbilical edge (Fig. 3E). The umbilical wall is high, nearly vertical to over-

hanging, and the flanks little inflated, converging to a flattened venter. Towards

the body chamber the section becomes a little more inflated. The ventral keel is

very prominent, with weak serrations, corresponding in number to lateral

ornament.

Ornament basically consists of radially pinched, sometimes overhanging

prominent umbilical (1) tubercles connected to stout, spirally elongated sub-

10 ANNALS OF THE SOUTH AFRICAN MUSEUM

D E F

Fig. 2. Protexanites (Protexanites) cycni (van Hoepen, 1965). A-C. SAS—Z834. D-F. Holo-

type SAS-Z651. x 1.

marginal (3) tubercles by means of low, fold-like, finely striate and virtually

straight ribs which occasionally bifurcate at the umbilical tubercles. Indistinct

intercalatories also occur, resulting in more submarginal (3) and external (5)

tubercles than umbilical ones. The external (5) tubercles are very thin and

spirally elongated and situated slightly forward of the submarginal (3) ones. The

distance between these latter two rows is very small, and in early stages of

growth they are connected by low, broad fold-like ribs. On the holotype, the

external (5) tubercles appear as a discontinuous, wavy lateral keel.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 11

Fig. 3. Protexanites (Protexanites) cycni (van Hoepen, 1965. A. SAS-Z808. B. SAS-Z834.

C-E. SAS-—Z832. A, C-E x 1;B x 1,1.

12 ANNALS OF THE SOUTH AFRICAN MUSEUM

SAS-Z834 shows details of the ontogeny (Figs 2A—C, 3B). On the innermost

whorls, up to a diameter of c. 6 mm, the whorls are rounded and devoid of

visible ornament. Beyond that diameter, umbilical (1) tubercles and very weak,

bifurcating fold-like ribs start appearing. Microscopic examination of the ribs

shows them to be ornamented by numerous radial striae. With the onset of

ornament, the whorl section changes and becomes rectangular. Traces of the

submarginal (3) tubercles become visible in the umbilical seam at a diameter

of about 14 mm. From then onward, ornament remains basically the same,

apart from the fact that the ribs tend to become more prominent on the body

chamber.

The external suture is relatively simple with a broad, asymmetrically bifid

lateral lobe (Fig. 4).

)

Perey td

Fig. 4. Protexanites (Protexanites) cycni (van Hoepen, 1965). Suture line of

SAS-Z832. Scale bar in millimetres.

Discussion

The main characteristics of this species are the subrectangular whorl

section with little-inflated flanks, ornamented by weak, flattened ribs with

occasional bifurcations and intercalations and by the weakly crenulate keel.

Van Hoepen (19655: 183) based this species on an immature juvenile

specimen, still fully septate at the largest diameter. On the basis of the present

material, the authors would place this specimen in Protexanites rather than in

Subprionocyclus, as suggested by Van Hoepen, although the dividing line

between the two taxa here becomes indistinct.

As far as the crenulate keel is concerned, comparisons may be drawn with

P. (P.) bourgeoisi and P. (P.) bontanti bontanti. Both species were recently

reviewed on the basis of the original material by Matsumoto (1966, 1970).

P. (P.) bourgeoisi has more sinuous ribs than P. (P.) cycni and exhibits a tendency

for the umbilical tubercles to migrate away from the umbilical wall up the

flanks, quite unlike those of P. (P.) cycni.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 13

P. (P.) bontanti s.s. in the sense of Matsumoto (1970: 235-237) has a

narrower umbilical diameter (31-33%) than P. (P.) cycni, and denser, more

flexuous ribbing. The whorl sections, however, are comparable apart from

slight differences in whorl height, possibly indicating genetic affinity. P. (P.)

bontanti shimizui was erected by Matsumoto (1970: 237) (see also Matsumoto

& Hirano 1976: 335) for a subspecies differing from the nominate subspecies in

possessing an entire ventral keel which is as high as the external tubercles. In

this respect P. (P.) bontanti shimizui is easily distinguished from P. (P.) cycni.

Matsumoto (1970: 235-237) discussed the affinities of P. (P.) bontanti s.s., and

little can be added apart from comment on the specimens figured by De Gros-

souvre (1894, pl. 17 (figs 2-3)). The specimen figured by De Grossouvre (1894,

pl. 17 (fig. 3)) does not belong to P. (P.) bontanti s.s. because of the presence

of a fourth row of tubercles on the dorsal part of the flanks on the outer whorl.

This may be an example of P. (Anatexanites).

Comparisons with other Protexanites s.s. species are as follows:

P. (P.) canaensis (Gerhardt) does not have as strongly developed umbilical

tubercles and is generally more weakly ornamented with a more rectangular

whorl section. 7

P. (P.) peroni Matsumoto has more flexuous ornament and apparently

lacks, or has very few, bifurcating ribs on the outer whorls.

P. (P.) planatus (Lasswitz) has much coarser ornament throughout.

In P. (P.) shoshonensis (Meek), as in P. (P.) bourgeoisi, the umbilical

tubercles tend to migrate away from the umbilical wall up the flanks.

P. (P.) strozzii (Desio) is difficult to interpret, but seems to have more

flexuous ornament on the outer whorl, although the inner whorls are com-

parable with those of P. (P.) cycni

P. (P.) eugnamtus (Redtenbacher) has coarse, but very closely-spaced

ornament, clearly differing from P. (P.) cycni.

Occurrence

Coniacian II to possibly V of Zululand.

Genus Paratexanites Collignon, 1948

(= Parabevahites Collignon, 1948)

Type species

Mortoniceras zeilleri de Grossouvre, 1894, by the original designation of

Collignon (1948: 45).

Diagnosis

The size of the shell is variable. Ornament consists of predominantly single

ribs, each bearing four rows of tubercles in the adult stage; umbilical (1), sub-

marginal (3), marginal (4), and external (5). In early stages the submarginal (3)

and marginal (4) tubercles are situated close together, sharing a single base.

Separation of these two tubercles takes place at varying diameters, and in some

14 ANNALS OF THE SOUTH AFRICAN MUSEUM

specimens presumably not at all. The marginal (4) tubercle develops by splitting

from the submarginal (3) one. The keel may be entire or undulating. Faint

indications of lateral keels joining the external (5) tubercles may occur in some

species.

Discussion

Wright (1957: L431-432) and Matsumoto (1970: 248) recognized two

subgenera:

Paratexanites (Paratexanites) (type species Mortoniceras zeilleri de Grossouvre

1894).

Paratexanites (Parabevahites) (type species Ammonites serrato-marginatus

Redtenbacher, 1873).

The main differences between the two subgenera are that in Paratexanites

s.s. the submarginal (3) and marginal (4) tubercles become separated, whereas

in P. (Parabevahites) they remain approximated, presumably also on the outer

whorls.

The Zululand material shows that it is difficult to decide when the two

rows of tubercles have separated sufficiently to be referred to Paratexanites s.s.,

rather than being retained in P. (Parabevahites). This criterion is extremely

ambiguous, and seems impossible to apply satisfactorily to the material: it

probably reflects ontogenetic rather than specific differences. Similar doubts on

this matter were also expressed by Young (1963: 80). The only species which

seem to retain the two rows of tubercles close together to great diameters are

the type species, Ammonites serrato-marginatus, Ammonites emscheris Schluter,

and Parabevahites sellardsi Young. Of these species, the first two are poorly

defined and enigmatic (see Matsumoto 1970: 249 and herein p. 15). Only

P. sellardsi is based on sufficient material to gain some idea as to intraspecific

variation.

In consequence, it is here considered that retention of Parabevahites is

probably unnecessary, and that it is better placed in the strict synonomy of

Paratexanites S.s.

Thus defined, species known to be referred to Paratexanites are:

Paratexanites compressus Matsumoto (1970: 255, pl. 36 (figs 4-5), text-fig. 13)

from the Santonian of Hokkaido.

?Paratexanites desmondi (de Grossouvre) (1894: 79) from the Coniacian or

Santonian of France.

Paratexanites emscheris (Schliiter) (1876: 41, pl. 42 (figs 8-10)) from the Coni-

acian of northern Germany.

Paratexanites muramotoi Matsumoto (1970: 257, pl. 37 (fig. 1), text-fig. 14))

from the Coniacian of Hokkaido.

Paratexanites orientale (Yabe) (Yabe & Shimizu 1925: 129, pl. 31 (figs 4-5),

pl. 33 (fig. 16)) from the Upper Coniacian of Hokkaido.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 15

Paratexanites rex Matsumoto (1970: 249, text-fig. 9(83)) (= Ammonites texanus

in Schliiter 1876: 41, pl. 12 (figs 1-3)) from the glauconitic marls of Stoppen-

berg, Germany.

Paratexanites serratomarginatus (Redtenbacher) (1873: 110, pl. 25 (fig. 2a—d))

from the Coniacian of Austria, France and Japan, and, doubtfully, Mada-

gascar and Zululand.

Paratexanites sellardsi Young (1963: 79, pl. 32 (fig. 7), pl. 36 (figs 3-5), pl. 37

(fig. 1), pl. 39 (fig. 4), pl. 49 (fig. 3), text-fig. 17) from the Upper Coniacian

of the Gulf Coast of North America.

Paratexanites zeilleri (de Grossouvre) (1894: 67, pl. 14 (fig. 1)) from the base

of the Craie de Villedieu, France.

Paratexanites umkwelanense (Crick) (1907: 228, pl. 15, (fig. 9-9a)) from the

Upper Coniacian to Lower Santonian of Zululand.

Paratexanites mikasaensis Matsumoto (1970: 258, pl. 37 (figs 2-3), text-fig. 15)

from an indefinite horizon of Upper Coniacian to Lower Santonian age in

Hokkaido.

Paratexanites collignoni (Fabre-Taxy) (1963: 19, pl. 1 (fig. 11)) from the Lower

Santonian in France.

Matsumoto (1970) recently discussed the scope of the genus, and few

comments only are needed on some of the above listed species.

P. zeilleri is monotypic. The German specimen included in the synonomy

of P. zeilleri by De Grossouvre (Ammonites texanus in Schliter 1867: 32 pars,

pl. 6 (fig. la—b) only) is a specimen of Texanites, according to Matsumoto

(1970: 249).

P. desmondi was erected by De Grossouvre (1894: 79) without providing

a figure. De Grossouvre included one of Schliter’s (1867, pl. 6 (fig. 3)) specimens

of Ammonites texanus in P. desmondi, but this specimen is to be regarded as an

inner whorl of P. rex rather than P. desmondi, according to Matsumoto (1970:

251). De Grossouvre’s description of P. desmondi is based on a fragment of a

whorl, with the first row of tubercles on the first third of the whorls, the second

on the second third of the whorl, and the third and fourth, which are rounded,

close together on the venter. The authors follow Collignon (1948: 72) in leaving

interpretation of the species open to doubt until the specimen is properly

illustrated.

P. emscheris is based on a fragment of an outer whorl, and is difficult to

interpret. This led De Grossouvre to include the species in the synonomy of

P. serratomarginatus, a view not supported here. P. emscheris, at any rate,

retains the Parabevahites row of doubled tubercles to a large diameter.

P. serratomarginatus is enigmatic. Redtenbacher based the species on seven

specimens, of which two were figured, an immature septate individual and a

body chamber fragment. The specimen figured by De Grossouvre (1894, pl. 16

(fig. la—b)) is still septate at a much larger diameter than Redtenbacher’s larger

figured specimen, and has coarser ornament. According to Matsumoto (1970:

16 ANNALS OF THE SOUTH AFRICAN MUSEUM

263) De Grossouvre’s specimen merits separation at subspecific level as P. ser-

ratomarginatus grossouvrel.

P. rex was erected by Matsumoto (1970: 249) for a specimen originally

identified as Ammonites texanus by Schluter (1872: 41 pars, pl. 12 (figs 1-3)), but

subsequently referred to P. emscheris by the latter (Schltiter 1876: 155).

The specimen from Madagascar described as Parabevahites dubius by

Collignon (1966a: 133, pl. 513 (fig. 2026)) has a distinct lateral tubercle, and the

submarginal (3), marginal (4), and external (5) tubercles situated close together

on an elevation in Parabevahites fashion. The species is most probably to be

referred to Plesiotexanites. Similarly Parabevahites? transitorius Collignon

(1966a: 80, pl. 488 (fig. 1970)), with Parabevahites-like inner whorls but penta-

tuberculate outer whorls, is to be referred to Plesiotexanites.

Species of Paratexanites are locally abundant in the Upper Conacian to

Lower Santonian sediments in the floodplains of the Mzinene and Hluhluwe

Rivers in Zululand, and provide important data on the phylogeny of the

Texanitinae.

The species to be described from Zululand are:

P. australis sp. nov.

P. pseudotricarinatum sp. nov.

P. umkwelanense (Crick)

P. sp. aff. P. emscheris (Schliter)

P. sp. aff. P. serratomarginatus (Redtenbacher)

According to current opinion, the origin of Paratexanites should be sought

in Protexanites. Young (1963: 79) drew attention to similarities between Para-

texanites zeilleri and Protexanites bourgeoisi, and Paratexanites sellardsi and

Protexanites planatus respectively, while Matsumoto (1970: 252) pointed to

similarities between Paratexanites compressus and Protexanites bontanti, and

Paratexanites mikasaensis and Protexanites canaensis respectively. Available

stratigraphic data, however, show that some of these Protexanites and Para-

texanites species occur together at the same stratigraphic level, or that Pro-

texanites may be even younger than Paratexanites locally.

The earliest known Paratexanites species in Zululand, P. australis sp. nov.,

is transitional between Protexanites and Paratexanites in remaining tritubercu-

late to a large diameter. As yet, however, no true Protexanites is known con-

necting to Paratexanites australis sp. nov. Available data in Zululand suggest

that P. australis sp. nov. is derived from the aberrant peroniceratid ‘Frauda-

toroceras’ besairiei van Hoepen, 1965b (Figs 5-7, 16A—C) with simple collignoni-

ceratid sutures. There probably was a Protexanites transitional stage between

‘Fraudatoroceras’ besairiei and Paratexanites australis sp. nov. as shown

below (p. 29).

This raises the possibility that Protexanites and Paratexanites may be

diphyletic as here interpreted. Matsumoto (1970: 230) suggested that Pro-

texanites could be derived from Subprionocyclus. In relatively weakly orna-

CRETACEOUS FAUNAS FROM SOUTH AFRICA NG)

Fig. 5. ‘Fraudatoroceras’ besairiei van Hoepen, 1965. Holotype SAS—Z756, the specimen figured

by Van Hoepen 1965 as plate 27, but lacking the outer septate whorl. x 0,95.

mented species such as P. (P.) bontanti, P. (P.) canaensis and P. (P.) cycni,

this line of descent seems feasible, whereas the stronger ornamented species,

such as P. (P.) bourgeoisi, P. (P.) shoshonense, and Paratexanites australis

sp. nov., appear closer to ‘Fraudatoroceras’ besairiei. On the basis of the present

evidence a division of Protexanites and Paratexanites along these lines would

be impracticable. In addition, P. australis sp. nov. shows occasional traces of

multiplication of the external tubercles, and corresponding nodes on the keel,

very reminiscent of Protexanites (Pleurotexanites), differing only in having a

doubled ventrolateral tubercle. This could again possibly be the origin of

Bevahites.

Plesiotexanites, which in younger stages has a Paratexanites-like arrange-

ment of the submarginal (3), marginal (4), and external (5) rows of tubercles,

may be derived from Paratexanites through addition of the lateral tubercle.

The holotype of Paratexanites pseudotricarinatum sp. nov. already shows faint

traces of a lateral tubercle, foreshadowing the development of Plesiotexanites.

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 6. ‘Fraudatoroceras’ besairiei van Hoepen, 1965. SAS-Z1522, with more prominent

lateral ornament than the holotype, and distinct concentric striae. x 1.

eee

cece

Fig. 7. ‘Fraudatoroceras’ besairiei van Hoepen, 1965.

Holotype SAS-Z756, showing suture line; after

Van Hoepen (1965: 32, fig. 9a). x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 19

Occurrence

Paratexanites occurs in the Coniacian to Santonian of western and central

Europe, north Africa and South Africa, Madagascar, North America, and

Japan.

Paratexanites australis sp. nov.

Figs 8-15, 16D-F

Holotype

SAS-Z1121 (Fig. 8), locality 73, lower reaches of the Mzinene River,

Zululand, St Lucia Formation, Coniacian IV—V to Santonian I.

Etymology

Refers to occurrence in southern Africa.

Material

Paratypes are NMB-—D1060a-b, from the same locality as the holotype;

SAS-H148/2, locality 14, a small quarry east of Riverview Sugarmill, St Lucia

Formation, Coniacian IV; SAS—Z180, SAS-Z186, and SAS-—H75c, from an

unknown locality near the Hluhluwe River estuary, probably locality 89-91,

St Lucia Formation, Coniacian IV-V; and BMNH-C81434-5, locality 88,

same Formation and age.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

LAI 83,0 31,0(37,3) 28,0(33,7) 1,11 37,0(44,6) 20 20

Z180 77,0 31,0(47,3) 27,0(35,1) 1,15 32,0(41,6) 10x2 10x2

H148/2 70,0 29,0(41,4) 27,0(38,6) 1,07 28,540,7) 12x2 12x2

Z186 123,0 38,0(30,9) 46,0(37,4) 0,82 54,0(43,9) 23 25

Description

The shell is relatively small; maximum diameter observed is 123 mm.

Coiling is very evolute, with a shallow dorsal zone of impression and an umbilical

width of the order of 40 to 45 per cent. The whorl section varies with ontogeny

(Fig. 15B—C), changing from depressed rectangular in the greater part of the

phragmocone, to square on the later part, to compressed on the body chamber.

Details of ontogeny can be observed in H148/2 (Figs 9-10) and SAM-—

PCZ5901 (Fig. 11D-E). The whorls are smooth up to a diameter of 4 mm,

thereafter low ribs start appearing, with prominent ventrolateral tubercles,

leaning or impressed into the umbilical wall of the succeeding whorl in H148/2

(Fig. 9). Umbilical tubercles start appearing at a diameter of 6,5 mm in H148/2,

and at 10 mm the umbilical edge is well defined, thus giving the whorl the

rectangular section characteristic of the species. The venter at this stage is

fastigiate with a distinct ventral keel and very indistinct lateral keels

(Fig. 11D-E). With increasing diameter at c. 12 mm, the ventrolateral tubercles

ANNALS OF THE SOUTH AFRICAN MUSEUM

"I X ‘fa1dIDSaq SDAVIOAOJOPNVA, OF Ie]UIIS

‘sjooy [ele}e] AABM SUIUIOJ Soposoqny [eUI9}x9 poyesuole oY} 9}ON,

‘IZLIZ-SWS edAlo[oH] “AOU ‘ds sypajsnv sapiupxajvsog °8 “St{

CRETACEOUS FAUNAS FROM SOUTH AFRICA 21

0 10

Fig. 9. Paratexanites australis sp. nov. Paratype SAS-Z148/2. Note the initial smooth

inner stage, followed by pointed ventrolateral and eventually conical umbilical and

long spinose ventrolateral tubercles. Scale bar in millimetres.

become forwardly projected over the venter, foreshadowing the development

of the external row of tubercles.

Ornament now consists of conical to radially elongated umbilical tubercles,

pointing laterally, connected by single, low and broad, often concave ribs to

well-developed rounded to spinose ventrolateral tubercles. The umbilical

tubercles are situated at the umbilical edge or are displaced slightly ventrally.

The external tubercles are poorly developed and appear as wavy lateral keels.

22,

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 10. Paratexanites australis sp. nov. Paratype SAS—H148/2. Note

the distinctly separated external tubercles. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 23

Fig. 11. Paratexanites australis sp. nov. A-B. Paratype NMB-D1060 with undulating lateral

keel. C. Holotype SAS—Z1121 before repair. D-E. Inner whorls of paratype SAM-—PCZ5901

to show early ornament and pseudotricarinate venter. A-C x 1; D-E x 3,9.

24 ANNALS OF THE SOUTH AFRICAN MUSEUM

Aww

Fig. 12. Paratexanites australis sp. nov. Paratype SAS—Z186. B illustrates the local multi-

plication of external tubercles on the venter of part of the phragmocone. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Fig. 13. Paratexanites australis sp. nov. Paratype SAS-Z186. x 1.

26 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 14. Paratexanites australis sp. nov. Paratype SAS—Z180. A illustrates local multiplication

of external tubercles on the venter of part of the phragmocone. x 1.

Beyond this trituberculate stage ornament in the material varies con-

siderably. The ventrolateral tubercles tend to become lower and broader, and

in some of the specimens (e.g. SAS-H75c, SAS—Z180, and NMB-D1060a)

(Figs 11A—B, 14) the formation of two distinct ventrolateral rows of tubercles

takes place, though still united by a single, common broad base. In SAS—Z186

(Figs 12-13) no distinct separation takes place and the specimen remains

trituberculate throughout. Similar differences are to be found in the ventral

ornament. The external tubercles may appear as two lateral keels as in SAS—

H75c, through slightly wavy discontinuous lateral keels as in SAS-Z1121

(Fig. 8), to distinct, though very elongated, clavi as in SAS-H148/2 (Fig. 10).

The central keel is wavy throughout and higher than the external tubercles (or

undulating lateral pseudo-keels). In places, the undulations on the keel are so

strong as to appear as a central row of tubercles. Furthermore, in specimens

SAS—Z186 (Fig. 12B) and Z180 (Fig. 14A) multiplication of the external tubercles

and corresponding undulations on the keel takes place locally. Lateral ornament

CRETACEOUS FAUNAS FROM SOUTH AFRICA Dah

continues weakly over the venter in places, creating, together with the undulating

lateral keels, a reticulate pattern over the venter (Fig. 13).

In SAS—Z186 (Fig. 12A) ornament weakens on the body chamber, and

two bifurcating ribs are present.

The suture line is rather variable as far as complexity of incision of the

elements and width of saddles is concerned, tending to be more complex than

in later collignoniceratid species (Fig. 15A).

Discussion

The species is here interpreted widely, but is identified mainly by the

depressed rectangular whorl section in the greater part of the phragmocone,

the prominent ornament and the late, or suppressed, division of the ventro-

lateral tubercles.

In the latter respect (i.e. late or indistinct appearance of quadrituberculate

stage), the species appears to be morphological intermediate between Pro-

texanites s.s. and Paratexanites. However, the only Zululand representative of

Protexanites, P. cycni, has completely different morphological features, and

seems to bear very little genetic relation.

fh G

--~.

Fig. 15. Paratexanites australis sp. nov. A. Suture

line of SAS—Z1121. B-C. Whorl section of early

stages of SAS—Z1120 and SAS—Z1121 respectively.

Scale bar in millimetres.

28 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 16. A-C. ‘Fraudatoroceras’ besairiei van Hoepen, 1965. SAS—Z1120a. D-F. Paratexa-

nites australis sp. nov. Paratype NMB-D1060b. The figure illustrates the similarity between

the aberrant peroniceratid ‘Fraudatoroceras’ besairiei and Paratexanites australis sp. nov. X 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 29

As far as overall morphology and relative complexity of the suture line is

concerned, the closest allied species is the tricarinate peroniceratid ‘Frauda-

toroceras’ besairiei van Hoepen (1965a: 36, pl. 27) (Figs 5-9, 16A—C) which

occurs at a slightly lower stratigraphic level. The latter has a similar depressed

whorl section on the phragmocone, and comparable ornament consisting of

radially elongated umbilical tubercles, single, slightly concave ribs and promi-

nent clavate ventrolateral tubercles. Through reduction of the umbilical width,

crenulation of the keel, separation of the lateral keels into external tubercles

and splitting of the ventrolateral tubercles, Paratexanites australis may be

derived from ‘Fraudatoroceras’ besairiei van Hoepen. As described above,

the present specimens display considerable variation in respect of these charac-

teristics, thus providing transitional forms between ‘Fraudatoroceras’ and Para-

texanites. SAS—Z186 (Figs 12-13), which apparently retains the trituberculate

stage throughout, provides the Protexanites stage connecting between ‘Frauda-

toroceras’ and Paratexanites australis. Two juvenile specimens, SAS—Z1120a

(Fig. 16A—C) and NMB-D1060b (Fig. 16D-F), show the great similarity

between ‘Fraudatoroceras’ besairiei and Paratexanites australis, the only differ-

ence being the presence of an entire lateral keel in the former compared to a

row of long, nearly touching external tubercles.

Apart from providing a link between the Texanitinae and Peronicera-

tinae, P. australis sp. nov. may also possibly provide material for derivation of

Plesiotexanites, Protexanites (Pleurotexanites) and other species of Paratexa-

nites: the inner whorls are remarkably similar to those of Plesiotexanites

matsumotoi sp. nov. to be described below from the Middle Santonian part

of the Umzamba Formation.

The occasional multiplication of the external tubercles, and corresponding

elevations on the central keel may perhaps be regarded as the forerunner of the

condition as found in Protexanites (Pleurotexanites) superbus (Collignon) from

which Bevahites and, possibly, Menabites may be derived.

Paratexanites umkwelanense (Crick) and Paratexanites pseudotricarinatum

sp. nov. to be described below (p. 44) may also be derived either directly from

P. australis sp. nov., or from a common source.

As far as whorl section and late appearance of the trituberculate stage is

concerned, the closest ally to P. australis seems to be P. orientalis (Yabe). In this

latter species, however, separation of the marginal and submarginal tubercles

is complete, and it would seem to fit a morphological position between P.

australis sp. nov. and P. umkwelanense (Crick).

Occurrence

Upper Coniacian to possibly Lower Santonian of Zululand.

30 ANNALS OF THE SOUTH AFRICAN MUSEUM

Paratexanites umkwelanense (Crick, 1907)

Figs 17-20A, 21-30

Mortoniceras umkwelanense Crick, 1907: 228, pl. 15 (fig. 9—9a).

Non Mortoniceras aff. umkwelanense Spath, 1921: 234, text-fig. D2.

Paratexanites umkwelanensis Matsumoto, 1955: 41, text-fig. 2.

Type

The holotype is BMNH C18134 from Umkwelane Hill, near Mfolozi,

Zululand. Exact locality and age unknown. (Here refigured as Figs 17—20A.)

Fig. 17. Paratexanites umkwelanense (Crick, 1907). Holotype BMNH-C18134. Inner

whorls of the specimen figured by Crick (1907, pl. 15 (fig. 9)). x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 31

A B

Fig. 18. Paratexanites umkwelanense (Crick, 1907). Holotype BMNH-C18134. Inner whorls

of the specimen figured by Crick (1907, pl. 15 (fig. 9)). x 1.

Material

SAS-36/3238-3239, Z975, NMB-D1060C, and PCZ-5694, locality 73,

Mzinene River, Zululand, St Lucia Formation, Coniacian IV—V to possibly

Santonian I; SAS—Z967, locality 91, Hluhluwe River floodplain, Zululand,

St Lucia Formation, Coniacian IV or V; SAS—Z870 and SAS-H199/8, locality

83, Mason’s Camp, False Bay; BMNH-C81505, locality 88, St Lucia Forma-

tion, Coniacian IV-V.

32 ANNALS OF THE SOUTH AFRICAN MUSEUM

~ yy

SES

Fig. 19. Paratexanites umkwelanense (Crick, 1907). Holotype BMNH-C18134. Outer whorl

of specimen figured by Crick (1907, pl. 15 (fig. 9)). x 0,75.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 33

Fig. 20. A. Paratexanites umkwelanense (Crick, 1907). Holotype BMNH-C18134, Outer

whorl of specimen figured by Crick (1907, pl. 15 (fig. 9)). x 0,75. B. Plesiotexanites stangeri

(Baily, 1855). BMNH-C19449. x 0,9.

34 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

Holotype

C18134 125,0 52,0(41,6) 50,0(45,2) 0,96 — 25 25

36/3238 63,0 24,0(38,1) 24,0(38,1) 1,0 22,0(34,9) 17 17

PCZ5694 112,0 41,0(36,6) 43,0(38,4) 0,95 44,0(39,3) 19 19

H199/8 140,0 44,0(31,4) 50,0(35,7) 0,88 59,0(42,1) 25 25

Z967 145,0 48,0(33,1) 48,0(33,1) 1,0 65,0(44,8) 22 2D

Z870 185,0 53,0(28,6) 65,0(35,1) 0,82 74,0(44,3) 11x2 11x2

Description

Coiling is evolute with an umbilical width of 35 to 45 per cent, increasing

with diameter. Whorl overlap is very little and the dorsal zone of impression

consequently extremely shallow. The whorl section is rounded subtriangular,

with greatest costal and intercostal width at the umbilical tubercle, which is

situated somewhat ventral of the umbilical edge (Figs. 21 B-—C).

Details of the early ontogeny are illustrated in SAS—36/3238 (Fig. 22)

where the smooth stage continues up to a diameter of 5 mm. Following that,

weak ribs with pinched, radially elongated umbilical tubercles appear, bifur-

cating occasionally. Ventrolateral tubercles become visible in the umbilical

seam at a diameter of 20 mm. In this specimen ornament remains weak up to a

(

Paratexanites umkwelanense (Crick, 1907). A. Partial suture of SAS-Z979.

B-C. Whorl sections of SAS—36/3239 and SAS-Z967. All x 1.

Fig. 21.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 35

Fig. 22. Paratexanites umkwelanense (Crick, 1907). SAS-36/3238. Showing inner whorls

to illustrate early ontogeny.

diameter of c. 30 mm. After this, ornament becomes very robust, with strong,

single ribs connecting radially elongated umbilical tubercles, displaced some-

what up the flanks, to strong, spinose ventrolateral spines leaning against the

umbilical wall or, in poorer preservation, prominent rounded nodes. Separation

of the ventrolateral tubercle occurs in SAM-—PCZ5694 (Fig. 23) at a diameter

of 55 to 65 mm. At diameters of c. 100 mm the submarginal, marginal, and

external rows of tubercles are equidistant. The keel is undulating in all the

specimens. In some specimens the undulations are so prominent as to create the

appearance of a central row of tubercles. In addition, low swellings may connect

the external tubercles spirally and across the venter, producing a reticulate effect

on the venter as in SAS—Z967 (Figs 24-26) and SAS-H199/8 (Fig. 27).

Ornament remains basically the same throughout the phragmocone. On

the body chamber, which consists of at least two-thirds of a whorl, ornament

becomes more prominent and acute, with distinct external tubercles protruding

far beyond the height of the weakened, undulating keel (Figs 28-30).

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 23. Paratexanites umkwelanense (Crick, 1907). SAM-—PCZ5694. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

. SAS-Z967. x 1.

1907)

Cri

ites umkwelanense (

Fig. 24. Paratexan

38 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 25. Paratexanites umkwelanense (Crick, 1907). SAS—Z967. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 39

RQQAAAWVWWWWYB Vw

A B

Fig. 26. Paratexanites umkwelanense (Crick, 1907). SAS-—Z967. x 0,87.

Discussion

This species was created in passim by Crick (1907: 228) by stating that

‘with the collection from False Bay was also a specimen . . . from Umkwelane

Hill referable to the genus Mortoniceras Meek. . . . Though related to the

Pondoland forms Mortoniceras soutoni and M. stangeri it is specifically distinct

therefrom and may be named M. umkwelanense.’

40 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 27. Paratexanites umkwelanense (Crick, 1907). SAS-H199/8. Showing the undulating

central keel. x 0,64.

The inner and outer whorls of the holotype are here refigured photo-

graphically (Figs 17—20A) to illustrate the distinct ornament in the adult stage

as well as the ontogeny.

In the adult, the species has very distinct ornament and is easily identified

by the spinosity of the umbilical, submarginal and marginal tubercles, and the

very clavate external tubercles protruding far above the undulating keel. The

inner whorls are distinguished by the stout ornament and rounded, subtrigonal

whorl section.

Matsumoto (1970: 255) pointed to the similarity between P. umkwelanense

and P. zeilleri and suggested that, if sufficient material were available, distinc-

tion between the two species may prove to be of subspecific value only. P. zeilleri

is difficult to interpret, being monotypic and having been figured once only, by

De Grossouvre. According to De Grossouvre (1894: 67) the specimen figured

CRETACEOUS FAUNAS FROM SOUTH AFRICA 41

Fig. 28. Paratexanites umkwelanense (Crick, 1907). SAS-36/3239. Body chamber fragment

illustrating generally spinose adult ornament. x 1.

42 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 29. Paratexanites umkwelanense (Crick, 1907). SAS—Z975. Atypical

body chamber fragment lacking well-defined umbilical tubercles. x 0,6.

by Schluter (1876, pl. 6 (fig. la—b)) as Ammonites texanus belongs to P. zeilleri.

Collignon (1948: 72) has, however, rather convincingly demonstrated that doubt

exists as to the conspecificity of the two specimens. This thus leaves us with a

single specimen on which to interpret P. zeilleri. P. zeilleri seems to differ mainly

in having a slightly wider umbilicus (c. 47% according to De Grossouvre’s

figure) and lacking the prominent development of the umbilical tubercle.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 43

Without having been able to examine De Grossouvre’s original specimen, the

authors are hesitant in referring the Zululand material to P. zeilleri, and prefer

to refer it to P. umkwelanense.

The specimen referred to as Mortoniceras aff. umkwelanense by Spath

(1921: 234, text-fig. D2) is definitely not a Paratexanites, but a good example of

Plesiotexanites to be described below.

Fig. 30. Paratexanites umkwelanense (Crick, 1907). NMB-D1060. Body

chamber fragment. x 0,6.

44 ANNALS OF THE SOUTH AFRICAN MUSEUM

P. umkwelanense is possibly derived from Paratexanites australis sp. nov.

directly or via P. orientalis (Yabe), through becoming quadrituberculate at an

earlier stage and in acquiring a more inflated whorl section. Similarities between

P. australis and P. umkwelanense are striking, as far as the strong development

of ornament in the relatively early stages of growth, the undulating keel, and

faint reticulate pattern on the venter are concerned.

P. orientalis differs from P. umkwelanense mainly in having a more depressed

whorl section in early stages of growth and less strongly developed ornament.

The adult whorl section of P. orientalis (see Matsumoto 1970: 254, fig. 11(85)b),

however, is very similar to that of P. umkwelanense, suggesting possible genetic

relationships. In the latter respect the apparent lack of undulations on the keel

of P. orientalis is disturbing.

P. sellardsi Young has also been compared with P. zeilleri, and Young

(1963: 80) states that the ‘differences between Parabevahites zeilleri and P.

sellardsi are not beyond the realm of variation within a species’. P. sellardsi,

however, is a distinct ‘Parabevahites’ with an approximated submarginal and

marginal tubercle. This latter characteristic is sufficient for separation of P. sel-

lardsi and P. umkwelanense.

P. rex Matsumoto has similar coarse ornament, but has a compressed

rectangular whorl section and lacks the spinose tuberculation of the adult of

P. umkwelanense.

P. muramotoi Matsumoto, P. compressus Matsumoto, and P. mikasaensis

Matsumoto, from Japan, can all be distinguished from P. umkwelanense on

account of their more compressed whorl section.

Differences between P. umkwelanense and P. pseudotricarinatum sp. nov.

are discussed below (p. 59).

Occurrence

Upper Coniacian, Coniacian IV—V to possibly Lower Santonian, San-

tonian I of Zululand.

Paratexanites pseudotricarinatum sp. nov.

Figs 31-44

Holotype

SAS-Z813 (Figs 32-33), locality 91, near the Hluhluwe River estuary,

Zululand, St Lucia Formation, Coniacian IV-V.

Etymology

Refers to the pseudotricarinate ornament on the venter.

Material

Paratypes are SAS—Z807, Z815b, Z818, Z975, and SAM-—PCZ5693, all

from the same locality as the holotype, St Lucia Formation, Coniacian IV-V;

CRETACEOUS FAUNAS FROM SOUTH AFRICA 45

Fig. 31. Paratexanites pseudotricarinatum sp. nov. Drawing

shows general ventral ornament of P. pseudotricarinatum

composed of a series of rectangles formed by weak lateral keels

and lateral ornament crossing over venter.

SAS-104, locality 89, boulder-strewn hill-slopes on the western boundary of

the False Bay Game Park, St Lucia Formation, Coniacian IV; SAS—Z2110 and

SAS-H198/1, locality 83, south-western shores of False Bay, Zululand, St Lucia

Formation, Coniacian IV; NMB-D1060, locality 73, lower reaches of the

Mzinene River, St Lucia Formation, Coniacian IV—V to possibly Santonian I;

NMB-D1364 was reported from north of the Hluhluwe River Estuary, probably

locality 86, St Lucia Formation, Coniacian IV; BMNH-C81505, between

localities 91 and 92, St Lucia Formation, Coniacian IV—V.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

Z813 105,0 — 38,0(36,2) — 30,0(37,1) 14x2 14x2

53,0 59,0 0,89

D1060 202,0 56,0(27,7) 65,0(32,2) 0,86 90,0(44,6) 21 21

Z815 163,0 51,0(31,3) 56,0(34,4) 0,91 77,0(47,2) D094, 22

PCZ5693 179,0 67,0(37,3) 67,0(37,3) 1,0 102,0(56,8) D2 2272

Z2110 205,0 70,0(34,1) 67,0(32,7) 1,04 93,0(45,4) 25 25

H198/1 187,0 61,0(32,6) 61,0(32,6) 1,0 81,0(43,3) 27 Di

Description

This is a very variable species but can be described as a Paratexanites in

which the ribs sweep forward over the umbilical wall and flanks without,

generally, forming a distinct umbilical tubercle. Ornament over the venter in

the adult is striking (Fig. 31). Faint lateral keels connect the external (5)

tubercles, whereas lateral ribbing continues weakened over the venter. The

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 32. Paratexanites pseudotricarinatum sp. nov. Holotype

Typical form. x 0,8.

SAS-Z813.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Fig. 33. Paratexanites pseudotricarinatum sp. nov. Holotype SAS-Z813.

Ribbing here forms slight loops over venter. Typical form. x 0,8.

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 34. Paratexanites pseudotricarinatum sp. nov. Paratype SAS-104.

Typical form. x 0,8.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

x 0,87.

1 form.

1Ca

tum sp. nov. Paratype SAS-104. Typ

tcarina

Fig. 35. Paratexanites pseudotr

50 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 36. Paratexanites pseudotricarinatum sp. nov. Var. A Paratype

costate variety. x 0,84.

SAS-Z807. Sparsely

CRETACEOUS FAUNAS FROM SOUTH AFRICA Sil

central keel is broad and undulating. This thus gives rise to ornament on the

venter comprising a series of rectangles.

Ontogeny

The holotype (Figs 32-33) is the only specimen with part of the innermost

whorls preserved. The smooth, rounded stage persists up to a diameter of 5 mm.

Beyond that, ribs start appearing, bearing pinched, radially elongated umbilical

tubercles. Rare bifurcations occur at this stage. The third row of tubercles

Fig. 37. Paratexanites pseudotricarinatum sp. nov. Var. B. Paratype NMB-D1060a.

Compressed variety. x 0,66.

Sy) ANNALS OF THE SOUTH AFRICAN MUSEUM

A B

Fig. 38. Paratexanites pseudotricarinatum sp. nov. Var. B. Paratype NMB—D1060a.

Compressed variety. x 0,76.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 53

Fig. 39. Paratexanites pseudotricarinatum sp. nov. Var. C. Paratype SAS-Z2110.

Variety with inflated whorls. x 0,68.

appears in the umbilical seam only at a relatively late stage, c. 25 mm. Here

these tubercles are flattened spinose, leaning against the umbilical wall. With

increasing diameter the ventrolateral tubercles become less spinose, and move

away from the umbilical seam, eventually to expose the fourth row of tubercles

at a diameter of about 60 to 70 mm. Simultaneously, the whorl section becomes

more rounded, lacking a distinct umbilical edge. Very faint indications of tuber-

culation become visible at midflank, foreshadowing the development of lateral

54 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 40. Paratexanites pseudotricarinatum sp. nov. Var. C. Paratype SAS-Z2110. Variety

with inflated whorls. x 0,8.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 55

Fig. 41. Paratexanites pseudotricarinatum sp. nov. Var. D. Paratype SAM-PCZ5693. Variety

with wider umbilicus and stronger ventrolateral ornament. x 0,57.

tuberculation in Plesiotexanites, but not distinct enough to merit reference to

that subgenus. On the body chamber the whorl section becomes even more

rounded, and the umbilical tubercle becomes virtually completely absorbed by

the ribs.

Variation

Variation in the material is extreme, and mainly affects the density of

ornament, strength of ornament over the venter, details of the whorl section and

umbilical width. There are virtually as many varieties as specimens, and since

the majority of specimens occur at more or less the same stratigraphic level,

formal separations of these different morphotypes would lead to a profusion

56 ANNALS OF THE SOUTH AFRICAN MUSEUM

A B

Fig. 42. Paratexanites pseudotricarinatum sp. nov. Var. D. Paratype SAM-PCZ5693. Variety

with wider umbilicus and stronger ventrolateral ornament. The ribs here pass strongly over

the venter on the body chamber. x 0,77.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 37

Fig. 43. Paratexanites pseudotricarinatum sp. nov. Var. E. Paratype NMB-D1364. Variety

with constrictions on body chamber resulting in serrate outline, and faint lateral tubercle on

flanks, foreshadowing Plesiotexanites development. x 0,6.

58 ANNALS OF THE SOUTH AFRICAN MUSEUM

of meaningless names. In consequence, the most obvious varieties are here

listed alphabetically with no formal taxonomic connotation.

Var. A, represented by SAS—Z807 (Fig. 36) differs from the typical form mainly

in being much more coarsely costate throughout.

Var. B, represented by NMB-D1060a (Figs 37-38) and SAS—Z815 has a more

compressed whorl section, with flattened flanks.

Var. C, represented by SAS—Z2110 (Figs 39-40) and SAS-H198/1 has a more

inflated whorl section and high umbilical wall with clearly defined umbilical

edge in the adult stage.

Var. D, is represented by one specimen only, SAM—PCZ5693 (Figs 41-42).

Here ornament over the venter in the adult stage is strongest, with the ribs

crossing the venter with little reduction of strength. Umbilical width in this

specimen is also greatest at 56,8 per cent.

Var. E, represented by NMB-D1364 (Fig. 43) has slight constrictions towards

the end of the phragmocone and on the body chamber, most notice-

able on the venter, resulting in a serrate outline. In addition, the whorl

section is most compressed in this specimen. Faint indications of a lateral

tubercle are visible on the body chamber.

Discussion

Unfortunately precise stratigraphic data are lacking, but it is to be expected

that those specimens with faint indications of lateral tubercles would be

youngest. Plesiotexanites collignoniforme sp. nov., described below, can be

‘.

-—----~

oo.

4-----.,

Ne ee ee

ne a er

(

ee eee eee

]

1.4}

o--------+--

—~

-~ ~_~

~ ~

Sa >. SoS

—) —_——

Sse

Samos)

—-~ =”

-----7-

aoa Seo ek

Fig. 44. i ais pseudotricarinatum sp. nov. Paratype NMB-D1060. Whorl section

and partial suture. Scale bar in millimetres.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 59

derived from Paratexanites pseudotricarinatum through compression of the

whorl section and addition of a lateral tubercle. The compressed specimen,

NMB-D1364 (Fig. 43), here designated Var. E, is thus a potential intermediate

form.

Paratexanites umkwelanense (Crick) is assumed to occur at more or less

the same stratigraphic level, and the two species appear related. P. umkwelanense

also has an undulating keel and may, in cases, also have indications of incipient

lateral keels. In typical forms, however, adult ornament is much more spinose

and conspicuous, and the ventral tubercles are elevated high above the keel.

P. pseudotricarinatum sp. nov. superficially resembles P. zeilleri as figured

by De Grossouvre (1894, pl. 14 (fig. 1)), but is easily distinguished by the

characteristic ventral ornament.

Occurrence

Coniacian IV-V, and possibly Santonian I of Zululand.

Paratexanites sp. aff. P. serratomarginatus (Redtenbacher, 1873)

Figs 45-47A

Compare:

Ammonites serrato-marginatus Redtenbacher, 1873: 110, pl. 25 (fig 2a—-d).

Paratexanites (Parabevahites) serratomarginatus (Redtenbacher): Matsumoto,

1970: 260, pl. 36 (figs 1-3), text-fig. 16.

Material

SAS-Z633, Z814 and Z865, all from locality 91, near the Hluhluwe River

Estuary, Zululand, St Lucia Formation, Coniacian IV-V.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

Z814 57,0 24,5(42,9) 21,0(36,8) Le, 21,0(36,8) 24 24

Z865 70,0 28,0(40,0) 28,0(40,0) 1,00 25,0(35,7) 22) oi,

Description

Coiling is relatively involute in the early stages, covering the ventral

quarter of successive whorls, but becomes more evolute towards the body

chamber. On the phragmocone the costal whorl section is subquadrate, as wide

as high, or slightly wider than high with maximum width at the umbilical edge.

In later whorls the section becomes more inflated, and subtrigonal (Fig. 45B)

with no distinct umbilical edge.

Ornament, especially on the inner whorls of the three available specimens,

differs considerably, ranging from dense, coarse ribbing with spinose ventro-

lateral nodes as in SAS—Z814 (Fig. 47A) to dense ribbing lacking strong ventro-

lateral ornament as in SAS—Z633 (Fig. 46). On the outer phragmocone whorls,

ornament is similar in the three specimens, consisting of strong, radially

elongated umbilical tubercles connected by weak, slightly prorsiradiately curved

60 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 45. Paratexanites sp. aff. P. serratomarginatus (Redtenbacher,

1873). SAS—Z814. Whorl section and partial suture. Scale bar in

millimetres.

Fig. 46. Paratexanites sp. aff. P. serratomarginatus (Redtenbacher, 1873). SAS-Z633.

Specimen with densely costate inner whorls. xX 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 61

ribs to approximated submarginal and marginal tubercles and a slightly more

distant row of clavate external tubercles.

The keel in all three specimens is undulating, though least noticeable in

SAS-Z814, the specimen with strong ornament on the inner whorls. Parts of

the body chamber are preserved in the two specimens, and here submarginal (3),

marginal (4), and external (5) tubercles are virtually equidistant.

The external suture is partly exposed in SAS—Z814 (Fig. 45A).

Discussion

It is unfortunate that the authors’ material of the species is limited, as it

would have been interesting to see whether there are any significant differences

between those specimens with coarse early ornament and those with more

delicate ornament. For the present all the specimens are referred to one species.

As far as the involute coiling and general nature of ornament on the outer

phragmocone whorls are concerned, there is strong resemblance to Para-

texanites serratomarginatus; especially when comparing SAS-Z814 (Fig. 47A)

to Redtenbacher’s figure (1873, pl. 25 fig. 2c—d).

This species, however, presents difficulties in interpretation. Of the seven

specimens available to Redtenbacher, only two were figured. Subsequent

interpretations of this species have differed considerably. Matsumoto (1970:

262 ff.) provided a good discussion on the extent and affinities of the species,

and erected a new subspecies, P. serratomarginatus grossouvrei, to accommodate

the French Villedieu specimens with undulating keels and stronger submarginal

tubercles. The Zululand material resembles the French subspecies closest in

possession of the undulating keel, but does not retain the double row of tubercles

to such a large diameter.

None of the figured specimens of P. serratomarginatus shows satisfactorily

whether the submarginal and marginal tubercles remain approximated through-

out or whether this feature is restricted only to the phragmocone. This is the

main reason for not accepting the subgeneric term Parabevahites, of which

P. serratomarginatus is the type species. Until this question is resolved, it is

advisable to refer to the Zululand material as P. sp. aff. P. serratomarginatus.

Not having seen the specimen, the authors cannot comment on the identity

of the large fragment (referred to P. serratomarginatus) mentioned by Collignon

(1948: 84), apart from the fact that the locality data appear to be incorrect.

Collignon suspected the specimen to have come from the vicinity of Skoenberg,

but it is more likely to have been collected in the lower reaches of the Mzinene

River (Kennedy & Klinger 1975, locality 73) where Paratexanites species are

known to occur. As yet Paratexanites species have not been recorded from the

Skoenberg itself by the authors, and this seems unlikely to happen, as the

youngest strata exposed there are Lower Coniacian.

This species is allied to P. umkwelanense, differing mainly in being more

narrowly umbilicate and having more inflated whorls and denser, though not as

prominently developed, ornament.

ANNALS OF THE SOUTH AFRICAN MUSEUM

SapluoxajoAdD °F

"TX ‘opounydis ose] oY} 9JON[ “WOT}aS Hoy *€/VIH-SVS “(OL8T “TeIN[YOS) st4ayasiua “gq “ye “ds

“S[JOYM JOUUL 9S1eOD YIM UaUTIDEdS “pI8Z-SVS “(ELST “Joyoequo}poy) smoursiDWOIDLAas “q “ye “dS sajiupxajosvg “WY “Ly ‘Sly

CRETACEOUS FAUNAS FROM SOUTH AFRICA 63

Occurrence

Coniacian IV-V of Zululand.

Paratexanites sp. aff. P. emscheris (Schliiter, 1876)

Figs 47B-48

Compare:

Ammonites emscheris Schliiter, 1876: 155, pl. 42 (figs 8-10).

Material

SAS-H1A/3, locality 22, Nyalazi River, Zululand, St Lucia Formation,

Coniacian IV.

Description and discussion

A large septate fragment collected from the basal beds exposed at locality 22

(Klinger & Kennedy 1975) is tentatively referred to Schliiter’s (1876) species.

The costal whorl section is subrectangular, higher than wide with well-developed

submarginal, marginal and external tubercles. The umbilical tubercles are

radially elongated, thus differing from Schliiter’s illustration (1876, pl. 42

(figs 8-10)).

__ Matsumoto (1970) recently discussed the scope of this species, pointing

out that it is not well defined. One of the specimens included under the name

Ammonites emscheris by Schliiter (1876: 155), previously described by him

(1872: 42 pars., pl. 12 (figs 1-3)) as Ammonites texanus, was regarded by Matsu-

moto as being sufficiently different from P. emscheris to merit separate specific

rank as Paratexanites rex. In the present specimen the umbilical tubercles are

radially elongated as in the latter species, but the whorl section is not as

compressed.

For the present it is considered best to refer to the available specimen as

P. sp. aff. P. emscheris.

Occurrence

Coniacian IV of Zululand.

Genus Plesiotexanites Matsumoto, 1970

Type species

Mortoniceras kawasakiti Kawada, 1929, by the original designation of

Matsumoto (1970: 267).

Diagnosis

The inner whorls remain trituberculate (1,3 +4,5) for a considerable period.

Eventually the ventrolateral (3-+4) node, which may be very large, divides into

two distinct tubercles, submarginal (3) and marginal (4). Simultaneously, or

later, a lateral (2) tubercle appears. Tubercles (3) and (4) may remain close

together, or separate completely, giving rise to normal Texanites ornament.

ANNALS OF THE SOUTH AFRICAN MUSEUM

, 1876). SAS-H1A/3. x 1.

ff. P. emscheris (Schliter

tes sp

48. Paratexan

ig.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 65

The lateral (2) tubercle may become prominent, remain inconspicuous, or

become absorbed in the flanks in later stages of growth.

Discussion

Matsumoto (1970: 274-280), in erecting Plesiotexanites as a subgenus of

Texanites, discussed its affinities extensively, and, apart from some new data

and comments on the phylogeny, it requires little elaboration.

According to Matsumoto (1970: 274-280) the following species were

considered to be representatives of Plesiotexanites:

Plesiotexanites kawasakii (Kawada, 1929) (Matsumoto 1970: 280, pl. 38

(figs 1-2), pl. 39 (fig. 1), pl. 40 (figs 1-2), pl. 41 (fig.1), pl. 42 (fig. 4), pl. 43

(figs 1-2), text-figs 21-22) from the Middle Santonian of Hokkaido.

Plesiotexanites pacificus Matsumoto (1970: 289, pl. 42 (fig. 2), pl. 45 (figs 1-2),

pl. 46 (fig. 4), text-fig. 24) from the Santonian of Hokkaido.

Plesiotexanites sanushibense (Yabe & Shimizu) (1925: 132, pl. 33 (figs 3-5))

from the Santonian of Hokkaido.

Plesiotexanites schlueteri Matsumoto (1970: 278, text-fig. 20) from an unspeci-

fied horizon in northern Germany.

Plesiotexanites shiloensis (Young) (1963: 89, pl. 46 (figs 1-4), pl. 54 (figs 4-7),

pl. 70 (figs 5-6, 8) text-fig. 24d) from the Upper Santonian of the Gulf

Coast of North America.

Plesiotexanites stangeri (Baily) (1855: 455, pl. 11 (fig. 2)) from the Lower to

Upper Santonian of South Africa, Madagascar, Hokkaido, and the Gulf

Coast of North America.

Plesiotexanites candelariae (Young) (1963: 102, pl. 56 (figs 1, 3-4), pl. 60 (fig. 8),

text-figs 20b, 28af, 29ae, 34af) from the Lower Campanian of the Gulf

Coast of North America.

Plesiotexanites thomsoni (Jones) (1966: 200, pl. 26 (figs 1-8), text-fig. 2) from

the Upper Coniacian or Santonian of California.

Plesiotexanites transitorius (Collignon) (1966a: 80, pl. 488 (fig. 1970A-—B)) from

the Middle Santonian of Madagascar.

Plesiotexanites yezoensis Matsumoto (1970: 294, pl. 44 lif, 2)) from the San-

tonian of Hokkaido.

Some doubtful contenders mentioned by Matsumoto were:

Texanites angolanus Haas (1942: 12, figs 8-10, pl. 15 (fig. 11)) from the Santonian

of Angola.

Parabevahites dubius Collignon (1966a: 133, pl. 513 (fig. 2026)) from the Upper

Santonian of Madagascar.

Mortoniceras omeraense Reeside (1927: 38, pl. 42 (figs 3-4), pl. 43 (figs 1-2))

from the Santonian of New Mexico.

Submortoniceras (?) aff. soutoni Reyment (1955: 95, pl. 33 (fig. la—b)) from the

Santonian of Nigeria.

66 ANNALS OF THE SOUTH AFRICAN MUSEUM

To the list of definite representatives of Plesiotexanites may be added:

Plesiotexanites matsumotoi sp. nov.

Plesiotexanites collignoniforme sp. nov.

from the Santonian of Zululand and Pondoland.

Plesiotexanites sp. indet. from the Santonian of Zululand, a doubtful contender.

The diagnostic characteristics of Plesiotexanites are restricted to the

ontogenetic development of ornament. Clearly this presents difficulties when

dealing with incomplete material, as Matsumoto (1970: 276) indicated in

discussing the affinities of Texanites angolanus and T. ralijaonai, both of which

lack the inner whorls. This should, however, in no way prevent the use of the

name Plesiotexanites for a group of generally evolute texanitids occupying an

intermediate position between Paratexanites or Protexanites and Texanites,

and which also probably gave rise to Reginaites.

The ontogeny of Plesiotexanites provides clues to its origin. The initial

trituberculate stage is like that of Protexanites s.s. The succeeding stages of the

various species differ in respect of the stage of appearance of the lateral tubercle

and division of the ventrolateral node. Thus, in P. stangeri the ventrolateral

node divides before the development of the lateral tubercle, thus mimicking a

Paratexanites type of ornament. With the development of the lateral tubercle,

the ornament is like that of Texanites s.s. In P. schlueteri the lateral tubercle is

retained for a short period only, thus the Texanites ornament here gives way to

Paratexanites ornament in the adult stage. In species such as P. thomsoni and

P. matsumotoi sp. nov. the lateral tubercle appears before division of the ventro-

lateral node, thus producing Protexanites (Anatexanites)-like ornament.

According to Matsumoto (1970: 277), Texanites shiloensis Young, which should

also be referred to Plesiotexanites, has inner whorls allied to Protexanites

(Miotexanites) minimus Matsumoto.

P. matsumotoi sp. nov. has inner whorls comparable to those of Para-

texanites australis sp. nov., and P. collignoniforme sp. nov. has inner whorls

similar to those of Paratexanites pseudotricarinatum sp. nov. or P. umkwelanense

(Crick).

Available data thus would seem to suggest that the origin of Plesiotexanites

is to be found in Protexanites s.1. or in Paratexanites.

The South African material of Plesiotexanites is of extreme interest in

providing links to both Reginaites and Texanites s.s., and is here accorded full

generic rank.

Occurrence

Definite occurrences of Plesiotexanites are in the Santonian of Japan,

Germany, Gulf Coast of America, Madagascar, Zululand, and Pondoland.

Other possible occurrences are in the Santonian of Angola, Cameroons and

Western Interior of North America.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 67

Plesiotexanites stangeri (Baily, 1855)

Figs 20B, 49-69

Ammonites stangeri Baily, 1855: 455, p. 11 (fig. 2).

Mortoniceras stangeri (Baily): Woods, 1906: 338, pl. 44 (fig. 1). Spath, 1921: 297, text-fig. D-1;

1922: 137, pl. 9 (fig. 2).

Mortoniceras stangeri (Baily) var. densicosta Spath, 1922: 138, pl. 5 (fig. 2).

Mortoniceras stangeri (Baily) var. sparsicosta Spath, 1922: 138, pl. 5 (fig. 1).

Texanites stangeri (Baily): Young, 1963: 88, pl. 45 (figs 1-3), text-fig. 25p.

Texanites stangeri (Baily) densicostus (Spath): Young, 1963: 86, pl. 42 (figs 3-4), pl. 43 (figs 2-4),

pl. 47 (figs 5-6), pl. 48 (figs 2, 5-6), pl. 71 (figs 1-4), text-figs 25c, e, g—h, 34c.

Texanites stangeri (Baily) var. densicosta (Spath): Collignon, 1966a: 72, pl. 484 (fig. 1958),

pl. 512 (fig. 2024).

Texanites stangeri (Baily) var. sparsicosta (Spath): Collignon, 1966a: 62 pl. 479 (fig. 1951).

?Parabevahites cf. emscheris Collignon, 1966a: 80, pl. 488 (fig. 1966).

Texanites stangeri subsp. aff. densicostus (Spath): Wolleben 1967: 1152, pl. 149 (fig. 1).

Texanites (Plesiotexanites) stangeri (Baily): Matsumoto, 1970: 285, pl. 41(45) (figs 2-4),

text-fig. 23 (97). Kennedy & Klinger, 1973: 102.

Texanites (Plesiotexanites) stangeri (Baily) sparsicosta (Spath): Kennedy & Klinger, 1973: 102,

pl. 6 (fig 3a—b).

Texanites (Plesiotexanites) stangeri (Baily) densicosta (Spath): Kennedy & Klinger, 1973: 102,

pl. 5 (fig. 2a—b).

Texanites (Plesiotexanites) stangeri (Baily) var. indet. Kennedy & Klinger, 1973: 103.

Fig. 49. Plesiotexanites stangeri (Baily, 1855). Copy of Baily’s original figure

(1855, pl. 11 (fig. 2)). Baily’s figure is a mirror image and partially restored.

See Figs 50 and 51.)

68 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 50. Plesiotexanites stangeri (Baily, 1855). Cast of holotype BMNH-C-73333. x 0,42.

Type

Holotype is BANH-C73333, the specimen figured by Baily (1855, pl. 11

(fig. 2)) (Fig. 49) from the Umzamba Estuary, Transkei, Umzamba Formation,

here refigured as Figures 50-51.

Material

BMNH-C19443, C19446, C19449-C19450, C19455-C19457, C19462,

C35623, C35627, C53144, SAM-K4827, K5544-K5545, K5547-K5551,

NMB-D1604, all from locality 1, from the Umzamba Formation at Umzamba

Fig. Si.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Plesiotexanites stangeri (Baily, 1855). Cast of holotype

BMNH-C-73333. x 0,48.

70 ANNALS OF THE SOUTH AFRICAN MUSEUM

Estuary, Transkei, Santonian II-III; DM-3505, UN-6557, UN-6564, UN-6570;

localities 4 and 5, subsurface deposits at Durban, Umzamba Formation,

Santonian III to Campanian I; several unmarked specimens in the Geological

Survey Collection, Pretoria, from excavations at locality 6, the Enseleni Game

Reserve, St Lucia Formation, Santonian II to Campanian I; similar fragments

from locality 14 in road cuttings near Mfolozi, St Lucia Formation, Santonian II

to Campanian I; a single fragment SAS—Z1971, locality 74, north-western part

of False Bay at Die Rooiwalle, St Lucia Formation, Santonian I-Campanian I;

and BMNH-C81533, locality 81, St Lucia Formation, Santonian I-II.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

C73333 320,0 60,8(19,0) 83,0(26,0) 0,73 179,2(56,0) 39 39

C19443 120,5 — 32,0(26,0) — 49,0(41,0) 24 24

64,0 — 16,6(26,0) — 30,6(47,9) 19 19

32,0 — 9,3(29,1) — 14,6(45,8) 17 19

C19446 135,0 — 39,0(28,8) — 69,0(50,3) 28 28

70,0 — 22,0(31,4) — 34,0(48,5) 20 26

34,0 10,0(29,4) — — 9,4(27,6) 19 Da

C19449 211,0 46,6(22,0) 55,7(26,4) 0,83 112,8(53,4) 30 30

112,8 —_ 34,2(30,4) — 40,0(57,1) 23 p24 |

C19450 138,6 — 34,6(25,0) — 74,6(53,8) — —

74,6 — 22,6(30,3) —_ 37,3(50,0) 18 32

C19455 137,0 36,0(26,2) 27,7(20,2) 1,29 67,0(48,9) 23 29

67,0 — 24,0(35,8) —_— 33,0(49,2) 19 7a

SAM-K5547 139,0 39,0(28,0) 41,0(29,4) 0,95 72,0(51,7) 23 29

72,0 25,0(34,0) 22,0(30,5) 1,1 38,0(52,7) 14 30

SAM-K5550 54,0 16,6(29,6) 15,0(27,7) 1,06 24,0(44,4) 19 21

Description

Coiling is very evolute, polygyral, with an average umbilical width of the

order of 40 to 50 per cent of the total diameter, but may reach up to 60 per cent

in some specimens. The whorl overlap is very little; generally less than 10 per

cent of the total whorl height. The species may grow up to a very large size;

the holotype is the largest known specimen with a diameter of 320 mm. The

majority of the Umzamba specimens measure between 100 to 200 mm.

Increase in whorl section is rapid. The innermost whorls have a square to

depressed whorl section, but, with increase in diameter, the section becomes

more rounded and gradually higher than wide with a rounded umbilical wall

and venter (Fig. 52A—B).

Ornament is variable due to ontogenetic change and intraspecific variation.

Ontogeny

In the first, Protexanites stage, which lasts up to c. 40 mm (Fig. 53B-C),

ornament is trituberculate, consisting of small, conical umbilical (1) tubercles,

and much larger, clavate ventrolateral (3-4) nodes, situated in the umbilical

suture and leaning against the umbilical wall of the succeeding whorl. The

external (5) tubercles are situated on either side of a prominent central keel,

CRETACEOUS FAUNAS FROM SOUTH AFRICA 71

Fig. 52. Plesiotexanites stangeri (Baily, 1855). A. Whorl section of holotype BMNH-C73333,

after Matsumoto (1970, text-fig. 23(97)A). B. Whorl section of var. sparsicosta, BMNH-—

C73333, after Matsumoto (1970, text-fig. 23(97)B). C. Partial suture of BMNH-C19444,

after Spath (1921, fig. D-—1a).

which is already developed at a diameter of 7,5 mm. These tubercles are joined

to the bases of the large ventrolateral nodes by low, broad connections. They

are not aligned with the ventrolateral (3-4) and umbilical (1) tubercles, but are

displaced somewhat forward. The external tubercles are very variable, sometimes

being elongated spirally to such an extent as to form discontinuous lateral keels

(Fig. 54E-F).

In the second stage, the ventrolateral tubercles begin to separate into two

2: ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 53. Plesiotexanites stangeri (Baily, 1855). A. SAS—Z1971. One of the two specimens

of the species thus far found in the False Bay region of Zululand. B-C. SAM-K5889. Juvenile

specimen showing pseudotricarinate inner whorls. x 1.

different rows through the splitting off on the ventral side of a new row, though

still connected by a common base (Fig. 54A—C). This is the ‘Parabevahites’ stage.

With increasing diameter the inner of these two rows migrates dorsad from the

spiral suture to complete the separation of the two rows. This is the ‘Para-

texanites’ stage.

In the third stage of development, faint indications of the lateral (2) tubercle

start appearing near the dorsal third of the flanks. The moment of appearance

and the strength of these lateral tubercles are very variable.

On the later part of the phragmocone, and on the body chamber, which

consists of one whorl on the holotype (Figs 50-51), bifurcations cease and

ribbing becomes single. The whorl section becomes progressively inflated

and towards the last part of the body chamber all lateral ornament weakens.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 73

Fig. 54. Plesiotexanites stangeri (Baily, 1855). A-C. SAM-—PCZ5686. Specimen illustrating

the Paratexanites stage of ontogeny, but with distinct separated external tubercles. D-F. SAM-—

K5550. Similar specimen with wavy lateral pseudo-keels. A, C, D-E x 1; B x 2.

74 ANNALS OF THE SOUTH AFRICAN MUSEUM

Intraspecific variation

Variation in density and prominence of ornament is extensive in this

species, and has led to the usage of names such as “sparsicosta’ and “densicosta’,

initially adopted by Spath (1922: 138). These varietal names are applicable

mainly to density of ribbing on the inner whorls as shown by Spath (1922,

pl. 5 (figs 1-2)) and here as Figures 57, 58. The present material shows that

virtually all transitions occur from closely ribbed specimens, SAM-—K5447

(Fig. 59), BMNH-C19443 (Fig. 60), via the holotype of the typical form

(Figs 50-51) to the holotype of var. ‘densicosta’ (Figs 55-57). Apart from

density, differences exist in strength of ornament on later parts of the shell.

Fig. 55. Plesiotexanites stangeri (Baily, 1855). BMNH-C19456. Holotype of var. densicosta.

(British Museum photograph.) x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 15

Specimens such as BMNH-C19462 (Figs 61-62A) and BMNH-C19449 (Figs

62B, 63) still have strongly developed ribbing and tuberculation on the outer

whorls, whereas specimen BMNH-C19459 (Figs 64-65) or BMNH-C19456

(Figs 55-56), the holotype of var. ‘densicosta’, are. virtually devoid of ornament

at the same diameters. Density of ribbing on the inner whorls of the latter two

specimens clearly shows that strength of ribbing on the outer whorls is inde-

pendent of density of ribbing on the inner whorls.

The point of appearance of the lateral (2) tubercle is extremely variable,

Fig. 56. Plesiotexanites stangeri (Baily, 1855). BMNH-C19456. Holo-

type of var. densicosta. (British Museum photograph.) x 1.

ANNALS OF THE SOUTH AFRICAN MUSEUM

Inner

Close-up of

icosta.

1855). BMNH-C19456

densi rac

ly,

whorls of var

texanites stangeri (Ba

Plesio

Fig

CRETACEOUS FAUNAS FROM SOUTH AFRICA

RES:

inner

. Close-up of

ta. Xc.3.

- SPAFSICOS:

Fig. 58. Plesiotexanites stangeri (Baily, 1855). BMNH-C19444

whorls of var

78 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 59. Plesiotexanites stangeri (Baily, 1855). SAM-K5447. x 1.

as is its ultimate strength. Lateral tubercles are well developed in BMNH-C19462

(Fig. 61) and C19449 (Fig. 63) compared to the faint lateral tuberculation in

BMNH-C19443 (Fig. 60) or BMNH-C19457 (Fig. 66).

Discussion

This species, together with Texanites soutoni, was the first texanitine recorded

from the Cretaceous deposits at Umzamba. Even so, it is rather rare in South

African collections and the bulk of the material is to be found in the collections

of the British Museum (Natural History).

CRETACEOUS FAUNAS FROM SOUTH AFRICA 719

Fig. 60. Plesiotexanites stangeri (Baily, 1855). BMNH-C19443. x 0,75.

80 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 61. Plesiotexanites stangeri (Baily, 1855). BMNH-C19462. x 0,75.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Fig. 62. Plesiotexanites stangeri (Baily, 1855). A. BMNH-C19462.

B. BMNH-C19449. x 0,9.

x Od:

82 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 63. Plesiotexanites stangeri (Baily, 1855). BMNH-C19449. x 0,7.

The type locality of the species was given as ‘cliffs off the South African

Coast near the Umtafuna and Umzambani Rivers’ (Baily 1855: 457). This is

currently known as Umzamba Cliff or locality 1 of the authors (Kennedy &

Klinger 1975: 281), and is the type section of the authors’ Umzamba Formation.

Recent collecting by the authors at the type section showed that the known time

range of P. stangeri in that section is Middle to Upper Santonian, with most

CRETACEOUS FAUNAS FROM SOUTH AFRICA 83

Fig. 64. Plesiotexanites stangeri (Baily, 1855). BMNH-C19459. x 0,7.

occurrences in the Upper Santonian. As far as could be ascertained, there

seems to be no stratigraphic difference in occurrence between the varieties

densicosta and sparsicosta or the typical form. These findings seem to be sup-

ported by Collignon (1966a) and Young (1963), although the authors doubt

if the Malagasy and South African biozonations are compatible with those

of the Gulf Coast. Collignon records var. densicosta and sparsicosta from the

Middle Santonian, and var. densicosta from the Upper Santonian of Mada-

; ANNALS OF THE SOUTH AFRICAN MUSEUM

Ray

>»

Fig. 65. Plesiotexanites stangeri (Baily, 1855). BMNH-C19459. x 0,9.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 85

gascar, whereas Young records var. densicosta from the Lower Santonian of

the Gulf Coast.

In consequence, the authors follow Matsumoto (1970: 288) in here

regarding the varietal names as mere convenient morphological terms without

taxonomic connotation.

The affinities of the species have already been discussed extensively by

Matsumoto (1970) and only little need be added.

Fig. 66. Plesiotexanites stangeri (Baily, 1855). BMNH-C19457. x 0,8.

86 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 67. Plesiotexanites stangeri (Baily, 1855). BMNH-C19446. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 87

Fig. 68. Plesiotexanites stangeri (Baily, 1855). BMNH-C19450. x 0,75.

The external (5) tubercles of some specimens of P. stangeri are extremely

elongated, creating the appearance of wavy lateral keels. Spath’s (1921: 297)

assertion that ‘Mortoniceras stangeri Baily sp. has tricarinate inner whorls’,

however, is a generalization, as the inner whorls of SAM—K5889 (Fig. 53B—C)

show. A single specimen, SAM—PCP5687 (Fig. 93C) tentatively referred below

to the genus Reginaites, is identical to P. stangeri in all respects except for

possession of two distinct continuous lateral keels at a relatively large diameter.

88 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 69. Plesiotexanites stangeri (Baily, 1855). SAM-—K4827. x 0,6.

The specimen figured by Woods (1906, pl. 44 (fig. 1)).

Baily’s figure of the holotype is reversed and somewhat reconstructed (see

Figs 49-51).

Occurrence

The geographic distribution of P. stangeri in southern Africa is curious.

Specimens are relatively abundant at the Umzamba Estuary, while a few speci-

mens are known from subsurface deposits at Durban and Richards Bay and

in isolated exposures near Umkwelane Hill.

This appears to be the northernmost occurrence of the species in South

Africa. A single doubtful specimen, SAS-K1971 (Fig. 53A), is known from

locality 74 at Die Rooiwalle at the north-western end of False Bay and another,

BMNH-C81533, from the Hluhluwe floodplain. To all appearances, P. stangeri

seems to be restricted to the shallow water sediments resulting from the south-

ward-progressing post-Lower Coniacian diachronous transgression (Kennedy

& Klinger 1971), being most abundant in the Middle and Upper Santonian

sediments at the Umzamba Estuary.

Other reports of this species are from the Middle and Upper Santonian

CRETACEOUS FAUNAS FROM SOUTH AFRICA 89

of Madagascar, an unknown horizon, probably Santonian of Hokkaido,

Japan, and the Lower Santonian of the Gulf Coast of the United States of

America.

Plesiotexanites collignoniforme sp. nov.

Figs 70-78

Holotype

SAS-Z1789 (Figs 70-71), locality 85, on the south-western shores of False

Bay, Zululand, St Lucia Formation, Santonian I.

Etymology

Refers to similarity to Texanites collignoni sp. nov.

Material

Paratypes are SAS-Z1790a—b, Z1791, Z2109, SAS-H100, H201/43-4,

BMNH-C81495-6, C81525-8, C81530-31, all from locality 85, on the south-

western shores of False Bay, Zululand, St Lucia Formation, Santonian I.

Dimensions

D Wb Wh Wb: Wh U Int. EXE:

Z1789 — 222,0 58,0(26,1) 67,0(30,2) 0,87 103,0(46,4) 37 27

Z2109 177,0 47,0(26,6) 57,0(32,2) 0,82 80,0(45,2) 31 31

H201/44 127,0 32,0(25,1) 39,0(30,3) 0,88 59,0(46,5) 30 30

Z1791 195,0 49,0(25,1) 59,0(30,3) 0,88 92,0(47,2) 28 28

Description

Coiling is very evolute, with an umbilical width of 45 to 47 per cent of the

total diameter, and a very shallow dorsal zone of impression. The whorl section

is nearly quadrate in the very early stages of growth, but soon becomes higher

than wide with a subtrigonal whorl section and little-inflated flanks. Towards

the body chamber the flanks become more inflated and the whorl section more

rounded (Fig. 72B).

SAS-Z1790a has the inner whorls preserved (Figs 73-74), permitting a

study of the ontogeny. The innermost whorls are completely smooth up to a

diameter of c. 8 mm; thereafter ventrolateral nodes start appearing in the

umbilical seam, and soon broad, flat ribs appear, some with incipient looping.

At a diameter of 20 mm umbilical tubercles start appearing at the dorsal ends

of these ribs. Ribbing is single throughout. Lateral (2) tubercles appear at a

diameter of c. 50 mm. Simultaneously, the ventrolateral (3) tubercles become

less spinose, and migrate away from the umbilical suture to reveal a fourth row

of tubercles.

With increasing diameter, ribbing becomes stronger, rursiradiate and

slightly sinuous, and tuberculation more prominent. Ribbing continues

obliquely over the rounded umbilical wall, but very weakly. The umbilical

tubercles (1) are situated high up on the umbilical wall, and tend to migrate up

90 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 70. Plesiotexanites collignoniforme sp. nov. Holotype SAS—Z1789. x 0,6.

the ventral part of the flanks. The lateral (2) tubercles are situated near the dorsal

third of the flanks, and, though weakly developed, appear most prominent due

to the strong development of ribbing in this area. The submarginal (3), margi-

nal (4) and external (5) rows of tubercles are situated closer to each other than

the first two rows (1 & 2). The marginal and external tubercles tend to be con-

nected by a thickened rib in Paratexanites fashion. The intertubercular area on

the venter is connected by a swelling, and the faint, undulating keel tends to

form a slight tubercle in this area. The external tubercles tend to be connected

CRETACEOUS FAUNAS FROM SOUTH AFRICA

fl)

)

x 0

Fig. 71. Plesiotexanites collignoniforme sp. nov. Holotype SAS—Z1789

92 ANNALS OF THE SOUTH AFRICAN MUSEUM

spirally by very faint ridges, thus creating a reticulate pattern over the venter,

as in Paratexanites pseudotricarinatum sp. nov., though weaker.

Towards the body chamber, the ribs become thinner, and the lateral

tubercles tend to become absorbed, followed by the umbilical and eventually

submarginal tubercles. The keel also becomes much weakened on the body

chamber.

The suture is broad with squat saddles and lobes (Fig. 72A).

Discussion

Barring slight details in density of ribbing, the species shows very little

variation, and is easily distinguished by the evolute coiling, slightly sinuous,

rursiradiate ribbing, low, indistinct undulating keel, and faint lateral lines

connecting the external tubercles and Paratexanites-like proximity of the external

and marginal rows of tubercles.

This species is morphologically intermediate between Paratexanites and

Texanites in being quinquetuberculate at a relatively small diameter, but in

retaining a Paratexanites-like ornament near the ventral part of the shell. Here

Fig. 72. Plesiotexanites collignoniforme sp. nov.

Paratype SAS-Z1970a. Whorl section and

partial suture line. Scale bar for suture in millimetres.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 93

distinction between Texanites s.s. and Plesiotexanites becomes subjective. This

species appears to be the source of Texanites collignoni and provides a link

between Paratexanites and Texanites. Relative stratigraphic position and

similarity of ornament over the venter (undulating keel, reticulate pattern, etc.)

leave little doubt as to the origin of the species, namely the plexus of Para-

texanites umkwelanense and Paratexanites pseudotricarinatum sp. nov. Similarly,

the whorl section, ornament, especially the rounded umbilical wall with the

Fig. 73. Plesiotexanites collignoniforme sp. nov. Paratype SAS—Z1970a.

<ul:

94 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 74. Plesiotexanites collignoniforme sp. nov. Paratype SAS—Z1790a. Close-up

of inner whorls to illustrate early ontogeny. xX c.5.

umbilical tubercle situated high up on the flanks, and the undulating keel are

reminiscent of Texanites collignoni sp. nov. (described below, p. 126), which

occurs stratigraphically higher up in the sequence. Similarly, Texanites texanum

s.l., also with undulating keel, may be derived from this species.

P. collingoniforme sp. nov. has a geographically separated, slightly younger

relative in T. umzambiense sp. nov. (described below, p. 167) from near the

base of the Umzamba Formation at its type section. In the latter, the external

and marginal tubercles are still approximated, and the keel is still undulating,

but the lateral tubercles appear a little earlier, and the whorl section is more

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Fig. 75. Plesiotexanites collignoniforme sp. nov. Paratype SAS—H100/1.

<oik.

ANNALS OF THE SOUTH AFRICAN MUSEUM

G Maes

Fig. 76. Plesiotexanites collignoniforme sp. nov. Paratype SAS-H100. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Fig. 77. Plesiotexanites collignoniforme sp. nov.

Paratype SAS-H100. x 1.

98 ANNALS OF THE SOUTH AFRICAN MUSEUM

inflated on the phragmocone. The isolation of the texanitine faunas between

Zululand and Pondoland could possibly have begun here.

Comparisons with other species are:

P. stangeri lacks the strong lateral ornament of P. collignoniforme and has a

more depressed whorl section.

P. matsumotoi sp. nov. has very strongly developed ventrolateral spines or nodes

in the early to middle stages of growth, and develops a lateral tubercle

much later. |

P. kawasakii (Kawada) (see especially Matsumoto 1970, pl. 43 (fig. 1)) has

dense, thin ribbing on the body chamber similar to the holotype of P. col-

lignoniforme, but has much coarser ornament on the inner whorls.

P. schlueteri Matsumoto bears some similarity to P. collignoniforme, but has

a very short Texanites-like stage.

Fig. 78. Plesiotexanites collignoniforme sp. nov. Paratype SAS-Z1791. x 0,64.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 99

Occurrence

Lower Santonian, Santonian I of Zululand.

Plesiotexanites matsumotoi sp. nov.

Figs 79-83

Mortoniceras aff. umkwelanensis Spath, 1921: 234, text-fig. D2.

Protexanites (Anatexanites) sp. aft. P. (A) nomii Klinger & Kennedy 1977: 98, figs 8B-E, 10A,

11.

Holotype

SAM-—PCP5683, Bed B7 locality 1, southern side of the Umzamba Estuary,

Pondoland, Transkei, Umzamba Formation, Santonian II.

Etymology

Named for Professor emeritus T. Matsumoto, Kyushu, Japan.

Material

Paratypes are SAS—BH9/121,50 from Upper Santonian borehole material

near Richards Bay; SAM-5491 from locality 10, Umkwelane Hill, Zululand,

St Lucia Formation, Santonian to Campanian; and BMNH-C19451 from an

unknown horizon within the Umzamba Formation at the Umzamba Estuary,

locality 1, Pondoland, Transkei.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

SAM-5491 240,0 71,0(29,6) 84,0(35,0) 0,84 98,0(40,8) 15x2 15x2

170,0 60,0(35,3) 61,0(35,9) 0,98 72,0(42,4) —— —

102,0 36,0(35,3) 37,0(36,3) 0,97 — 10x2 10x2

Description

Coiling is evolute, with an umbilical diameter of 40 to 46 per cent of the

total diameter. The whorl section is angular in the early stages, becoming more

rounded on the outer whorls. On the inner whorls, the section is subrectangular,

broader than high, but with increasing growth the section becomes higher than

wide, with a broadly rounded venter and no distinct umbilical wall.

Ontogenetic development can be seen in SAM-—PCP5683 (Fig. 79). The

very innermost whorls are not preserved, but at a diameter of 5 mm the whorl

section is round, with slight swellings in the umbilical wall. From 5 to 8 mm

diameter, strong, spinose ventrolateral spines which lean against the umbilical

wall start appearing. Beyond 8 mm, low, rounded ribs corresponding in number

to the ventrolateral spines appear, and at 12 mm the first small umbilical (1)

tubercles are visible. Beyond that diameter, ornament becomes stronger, con-

sisting of very strong ventrolateral spines, leaning against the umbilical wall

and smaller, slightly inward-pointing umbilical tubercles, connected by low,

100 ANNALS OF THE SOUTH AFRICAN MUSEUM

broad ribs numbering about 15 per whorl (Fig. 79). Occasional small, yet

distinct intercalatory umbilical tubercles not associated with any ribs or ventro-

lateral spines occur. Very faint lateral (2) tubercles start appearing at a diameter

of c. 60 to 70 mm, becoming increasingly stronger with growth. At this diameter

the ventrolateral ornament is fully exposed on the holotype. The ventrolateral

(3+-4) tubercles are no longer spinose, but appear as prominent rounded bosses,

indicating that the original spines became detached at a basal septum. The

external (5) tubercles are distinctly separated, though very elongated. The

central keel is lower than the train of external tubercles and appears smooth.

At diameters between 70 and 80 mm, the strong ventrolateral (3-4) nodes

begin to show a tendency towards doubling, with the formation of a small

clavate marginal tubercle (4), and a larger, rounded submarginal (3) tubercle.

This eventually leads to the development of a normal quinquetuberculate

Texanites ornament as shown by SAM-5491 (Figs 80B-81), although the

lateral tubercle is never very well developed.

On the later part of the phragmocone the tubercles are virtually equi-

distant. The umbilical ones are pointed and radially elongated; the lateral

ones small and conical, and the submarginal, marginal and external ones

clavate in ascending order. On the last part of the phragmocone and on the

body chamber all ornament weakens considerably, and ribs become very

narrow (Fig. 81).

Discussion

In the authors’ (Klinger & Kennedy 1977) previous description of part

of the present material, the eventual splitting of the ventrolateral node was not

noticed due to incomplete exposure; hence their tentative reference to Pro-

texanites (Anatexanites). The Umkwelane Hill and some Pondoland specimens,

however, clearly show the Plesiotexanites affinity of the material.

The inner whorls resemble those of Paratexanites australis sp. nov., and

this species can possibly be derived from the latter. The spinose ventrolateral

nodes which remain undivided for a great distance are common to both species.

Further comparisons may be made with Plesiotexanites kawasakii

(Kawada), but in this species the ventrolateral spines are divided into weak inner

and stronger outer tubercles at the onset of the appearance of the lateral tubercle.

Thus the quinquetuberculate stage follows immediately after the trituberculate

stage, whereas Plesiotexanites matsumotoi has a quadrituberculate P. (Ana-

texanites)-like stage before the quinquetuberculate stage.

P. thomsoni (Jones), of Upper Coniacian or Lower Santonian age, is similar

in retaining a quadrituberculate stage to a large diameter (200 mm +) before

the quinquetuberculate stage, but differs considerably in ornament and general

shape. In P. thomsoni there is a marked decrease in size of umbilical and ventro-

lateral tubercles at the onset of the appearance of the lateral (2) tubercles, which

does not happen in P. matsumotoi sp. nov., and it also has much finer, denser

costation than the latter.

101

CRETACEOUS FAUNAS FROM SOUTH AFRICA

AGS WG

wet

NSS

Holotype SAM-—PCP5683. x 1.

ites matsumotoi sp. Nov.

iotexani

Fig. 79. Ples

102 ANNALS OF THE SOUTH AFRICAN MUSEUM

A B

Fig. 80. Plesiotexanites matsumotoi sp. nov. A. Holotype SAM-—PCP5683.

B. SAM-5491. A x 1; B x 0,5.

The weak, occasional intercalated umbilical nodes in P. matsumotoi are

also possibly of specific significance.

P. collignoniforme sp. nov. has a slower rate of expansion, and is more

weakly ornamented throughout, than P. matsumotoi.

There is slight superficial resemblance to Paratexanites umkwelanense as

Spath (1921: 234) had probably implied in referring the large specimen, SAM-—

CRETACEOUS FAUNAS FROM SOUTH AFRICA 103

Fig. 81. Plesiotexanites matsumotoi sp. nov. SAM-5491. This is the specimen

originally described by Spath (1921: 234) as Mortoniceras aff. umkwelanense.

<0)52;

5491, tentatively to that species. The presence of lateral tubercles, however,

clearly precludes inclusion of this specimen in Paratexanites.

This species is of additional importance in that it seems to connect to the

Reginaites species described below (p. 111).

Occurrence

Middle to Upper Santonian of Pondoland, and Zululand.

104 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 82. Plesiotexanites matsumotoi sp. nov. Paratype BMNH-C19451. (British Museum

photograph.) x 1.

105

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Fig. 83. Plesiotexani

—

28)

bax

(ely fe

2 5

3§

= oO

an oe

Soc

nH A

(Brit

106 ANNALS OF THE SOUTH AFRICAN MUSEUM

Plesiotexanites ? sp. indet.

Fig. 84

Material

A single specimen, SAS—76B from locality 74, north-western end of False

Bay at Die Rooiwalle, Zululand, St Lucia Formation, Santonian I to Cam-

panian I.

Fig. 84. Plesiotexanites ? sp. indet. SAS-76B. x 0,8.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 107

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

166,0 c.40(c.24) c.54(c.32) c.74 76,0(45,8) 33 33

Description

The available specimen is septate throughout, and lacks the inner whorls.

Coiling is evolute, with an umbilical diameter of 45,8 per cent. The whorl

section is distinctly higher than wide, with a very shallow dorsal zone of impres-

sion, widely rounded umbilical wall passing into weakly inflated flanks without

giving rise to a distinct umbilical edge, and with a narrow, rounded venter.

Ornament is weak throughout, consisting of widely spaced (c. 33 per whorl),

gently forwardly curved single ribs bearing five feeble rows of tubercles.

The umbilical (1) tubercles appear to arise in the umbilical wall, and are small

and radially elongated. The lateral (2) tubercles are smallest, conical, and

situated just dorsad of midflank. The submarginal (3), marginal (4) and external

(5) rows are progressively clavate, and situated closer to each other than the

other rows. The keel is inconspicuous and much lower than the external

tubercles.

The suture line is unknown.

Discussion

Lacking the inner whorls, it is uncertain whether this specimen is referable

to Texanites or to Plesiotexanites. The very weak ornament and com-

pressed whorl section is totally different from any of the other texanitine species

available in South Africa. On account of the weak development of the lateral

tubercles and the proximity of the ventral three rows of tubercles, the specimen

is very tentatively referred to Plesiotexanites.

As far as looseness of coiling is concerned, there is some similarity to

P. stangeri, but the latter has a more angular whorl section and stronger

ornament.

In terms of relative proportions, the Zululand specimen falls within the

limits of Texanites venustus Collignon (see Collignon 1966a: 74, pl. 485

(fig. 1960)) and Texanites hourcqi var. souromarayensis (see Collignon 1966a: 74,

pl. 485 (fig. 1959)), both from the Middle Santonian of Madagascar, but lacks

the bifurcating ribs of these two species.

Occurrence

Santonian of Zululand.

Genus Reginaites Reyment, 1957

( ?= Reymentites Matsumoto, 1965) _

Type species

Peroniceras (Reginaites) quadrituberculatum Reyment (1957, pl. 11

(fig. la—b), text-fig. 7) by the original designation of Reyment (1957: 65).

108 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis

Coiling evolute. Venter generally tricarinate throughout, but early whorls

may possibly have wavy lateral keels. Central keel stronger than lateral keels.

Ornament on the flanks in early stages is bituberculate; umbilical (1) and

ventrolateral (3-+4). With increasing diameter, the ventrolateral tubercles

divide into a row of clavate marginal (4) and a more rounded row of sub-

marginal (3) tubercles. Lateral (2) tubercles appear later, or not at all, and are

generally weaker than the other tubercles. Towards the body chamber, ornament

may weaken. The suture is of collignoniceratid type, with little-incised elements.

MIDDLE SANTONIAN------------- LATE SANTONIAN

Oe 8 G © ean: eee eas

4H 14 1 ot \ ‘

> ry io Hy bh UH fn Kh fi

eS = 1) C O} m On en { \ \ \ '

m —) Sa. Sm. bo OF

can (GID) eS) ee SSS

GDIGaeE)

z z icnomey acne iA |

Y Herons, lof fa 10% Pa oH

Soacg ii iy ore ee

oO iO’ iO’ vow ox ids | ny 8

ap Sak Or, Os Ps SOS

Zz SSe

Sere

A9vIS

Ava

| Om

Dy s

©)

GID

loyOlunsyew J |

WUaWAal “yy |

nynz ‘y

Fig. 85. Diagram to illustrate probable evolutionary relationship and known ontogenetic

changes in South African representatives of genus Reginaites.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 109

Discussion

Reginaites poses difficulty in interpretation, being poorly represented in

numbers. Reyment (1957: 65) introduced the genus as a subgenus of Peroniceras,

based on a single specimen from the Asu River, near Agbani, Nigeria, then

believed to be of Upper Coniacian age. Apart from the type species, here repro-

duced as Figures 87C, 89, Reyment also included Peroniceras leei Reeside

1927: 40, pl. 42 (figs 1-2), pl. 43 (figs 3-4)), a Lower Campanian species, in

Reginaites. Young (1963: 92) added another species, Reginaites durhami, from

the base of the Lower Campanian, to the genus.

Since then, however, new taxa have been erected for species with tri-

carinate venters and simple collignoniceratid suture, thus obscuring differences

between the Texanitinae and Peroniceratinae, and also within the latter.

These taxa are:

Fraudatoroceras van Hoepen, 1965 (type species Fraudatoroceras besairiei

van Hoepen, 1965a: 36, pl. 27, text-fig. 9a—b) from the Coniacian of

Zululand.

Cobbanoceras Matsumoto, 1965 (type species Cobbanoceras tanakai Matsumoto,

1965: 220, pl. 37 (fig. 3), pl. 38 (fig. 1), pl. 39 (fig. 1) text-figs 4-5) from the

Santonian of Hokkaido and ?Coniacian of California.

Reymentites Matsumoto, 1965 (type species Reymentites hataii Matsumoto

1965: 240, pl. 42 (fig. 3), text-figs 19-20) from the Urakawan (Coniacian

and Santonian) of Hokkaido.

As far as diagnoses are concerned, Fraudatoroceras van Hoepen and

Cobbanoceras Matsumoto appear to be synonymous. Both are tricarinate,

bituberculate, widely umbilicate and have simple sutures similar to those of

Gauthiericeras (see Van Hoepen 1965a: 35-6; Matsumoto 1965: 219-220).

If the taxa are, indeed, the same, Cobbanoceras is a junior synonym of Frauda-

toroceras, as Van Hoepen’s work precedes that of Matsumoto by four months

(27 July 1965 v. 20 November 1965). Full details are to be given in the authors’

pending revision of the Peroniceratinae.

According to Matsumoto (1965: 239) Reymentites resembles Reginaites

in being trituberculate or quadrituberculate, but differs from the latter in

having the tubercles spaced more or less equidistant, rather than having the

ventrolateral tubercles (3-+-4) situated close together. This relationship would

thus be somewhat analogous to that between Paratexanites and ‘Parabevahites’.

The holotype, and, indeed, only individual available of Reymentites hataii, is a

wholly septate individual and probably immature, but does show the equi-

distant tuberculation. Apart from the latter species, Matsumoto (1965: 239)

also referred Reginaites durhami Young to genus Reymentites. The holotype

of this species lacks the inner whorls, and the equidistant tuberculation present

may well be regarded as the normal result of ontogenetic change in Reginaites

as here interpreted. Reymentites is thus provisionally included in the synonymy

of Reginaites, contrary to the views of Wiedmann (1978: 670).

110 ANNALS OF THE SOUTH AFRICAN MUSEUM

Species which may thus be referred to Reginaites are:

Reginaites durhami Young (1963: 92, pl. 39 (fig. 2), pl. 49 (figs 1-2, 4), text-

fig. 22bc) from the Lower Campanian of the Gulf Coast of North America.

Reginaites gappi Wiedmann (1978: 668, pl. 3 (figs 1-3), text-figs 2c, 3b) from

the Upper Santonian of Austria.

Reymentites hataii Matsumoto (1965: 240, pl. 42 (fig. 3), text-figs 19-20) from

the Urakawan (Coniacian and Santonian) of Hokkaido.

Reginaites leei (Reeside) (1927: 40, pl. 42 (figs 1-2), pl. 43 (figs 3-4)) from the

Lower Campanian of New Mexico.

Reginaites quadrituberculatum Reyment (1957: 65, pl. 11 (fig. la—b), text-

fig. 7) from the Upper Coniacian? of Nigeria.

To this list may be added two new species:

Reginaites reymenti sp. nov. from the Upper Santonian or Lower Campanian

of Zululand.

Reginaites zulu sp. nov. from the top of the Upper Santonian of Zululand.

Specific differentiation between the species is based mainly on the whorl

section, presence or absence of lateral (2) tubercles and stage of splitting (if at

all) of the ventrolateral tubercle and ornament on the body chamber.

Unfortunately, dating of all the species is not satisfactory. Reymentites

hataii cannot be dated more accurately than Urakawan (Coniacian and San-

tonian). Reginaites leei and R. durhami are of definite Lower Campanian age,

whilst the Zululand specimens are not older than Upper Santonian. The holotype

of R. quadrituberculatum was collected by R. Blaser in beds above undoubted

Coniacian and was thus tentatively dated as Upper Coniacian. According to

Reyment (pers. comm. 21 November 1977), however, there is no evidence to

gainsay a Santonian age for this species, and in the light of the present know-

ledge this would be a more reasonable alternative.

Thus, unless we are here dealing with a polyphyletic group, or hetero-

chronous homoeomorphic groups, Reginaites seems to be a Santonian to

Lower Campanian genus.

Similarities between Reginaites and Plesiotexanites are striking. Apart

from the presence of lateral keels versus an external (5) row of tubercles, there

is no significant difference. This similarity had already been remarked upon by

Young (1963: 93).

As in other known occurrences, Reginaites does not occur in great numbers in

Zululand, but from the specimens available, a phylogenetic sequence as out-

lined in Figure 85 could be envisaged. Plesiotexanites matsumotoi sp. nov., with

large ventrolateral spines or nodes, appears most suitable as ancestral form in

South Africa. Through further lengthening of the already long external

tubercles, the tricarinate venter is obtained. The ventrolateral (3-+-4) tubercles

remain intact to greater diameters and the lateral (2) tubercle appears later

and eventually not at all, thus giving rise to Reginaites zulu sp. nov. via R.

reymenti sp. nov. A further possible trend is that the central keel becomes

CRETACEOUS FAUNAS FROM SOUTH AFRICA 111

progressively more prominent at expense of the lateral keels and the venter

more fastigiate, as in R. zulu. From this it would be possible to connect to

Neogauthiericeras.

Matsumoto (1965: 240) suggested that Reginaites, Reymentites and Cob-

banoceras may be grouped together in a new subfamily. In view of the close

similarity and relationship between Plesiotexanites and Reginaites, however,

separation at this level is unacceptable, even if this inclusion deviates from the

unicarinate character of the rest of the texanitids.

Occurrence

Stratigraphic data on Reginaites species are still confusing, as discussed

above. Current data seem to indicate that the genus is restricted to the Santonian

to Lower Campanian of Austria, Nigeria, Gulf Coast of North America,

Hokkaido, Zululand, and, questionably, Pondoland.

Reginaites reymenti sp. nov.

Figs 86, 87A-B, 88

Holotype

SAS-Z1986 (Fig. 87A-B), locality 74, Die Rooiwalle, Zululand, St Lucia

Formation, Santonian I to Campanian I. °

Etymology

Named for Professor R. A. Reyment, Uppsala.

Material

Paratypes are SAM—PCZ5877, PCZ5887—PCZ5888 from an unlocalized

collection, but presumably also from Die Rooiwalle, as is the holotype.

Description

All the specimens are fragmentary, but together give a good idea of a

complete individual.

Coiling is evolute, with an umbilical diameter of about 44 per cent. The

whorl section in the early whorls is rectangular, wider than high, but becomes

more inflated with a rounded venter in later whorls, resulting in a dome-shaped,

but still wider than high whorl section.

On the earliest whorls preserved, at a diameter of c. 30 mm, ornament

consists of small, pointed, conical, to radially elongated umbilical (1) tubercles,

and strong, bullate, slightly clavate ventrolateral nodes connected by low,

broad, widely-spaced single ribs. The venter has three keels of which the central

one is strongest. At larger diameters, the ventrolateral nodes begin dividing

into two: a rounded submarginal (3) node and a smaller, clavate marginal (4)

tubercle. The first sign of division appears at c. 60 mm diameter.

112 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 86. Reginaites reymenti sp. nov. A-B. Paratype SAM-PCZ5877. C-D. Paratype SAM-

PCZ5887. Note the faint lateral tubercle on the upper end of A. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 113

Fig. 87. A-B. Reginaites reymenti sp. nov. Holotype SAS—Z1986. C. Reginaites quadrituber-

culatum Reyment, 1957. Holotype BMNH-—C48040. x 1.

114 ANNALS OF THE SOUTH AFRICAN MUSEUM

On specimens SAM-PCZ5877 and SAS-—Z1986 (Figs 86A-B, 87A-B),

which illustrate development at larger diameters, ribbing becomes prorsi-

radiate, the marginal (4) tubercle migrates forward, ahead of the submarginal (3)

tubercle on the venter. Further development differs somewhat in these two

specimens. At the largest diameter preserved on SAS-Z1986 (Fig. 87A-B),

ornament remains trituberculate, i.e. umbilical (1), submarginal (3) and marginal

A B

Fig. 88. Reginaites reymenti sp. nov. Paratype SAM-PCZ5888. Showing part of body

chamber with sharpened ribbing. x 1.

115

CRETACEOUS FAUNAS FROM SOUTH AFRICA

1957. Holotype BMNH-C48040. x 1.

Fig. 89. Reginaites quadrituberculatum Reyment,

116 ANNALS OF THE SOUTH AFRICAN MUSEUM

(4). On SAM-PCZ5877 (Fig. 86A-B), however, which is of similar size to the

outer whorl of the holotype, a small but distinct lateral (2) tubercle appears.

In SAM-PCZ5888 (Fig. 88), which probably belongs to the same individual

as the former specimen (SAM-—PCZ5887), part of the body chamber is pre-

served. Here, all the tubercles tend to become incorporated in the ribbing,

which becomes sharper and apparently more distantly spaced. The ribs now are

prorsiradiate over the flanks, bend sharply forward between the submarginal (3)

and marginal (4) tubercles, and then continue as thin riblets up to the lateral

keel. Preservation in this specimen is rather poor but it does appear that the

lateral (2) tubercle again disappears on the body chamber, or stays feeble

throughout.

Discussion

This species is characterized by the strong, bullate ventrolateral tubercles

on the inner whorls, weak development of the lateral (2) tubercle and tricarinate

venter. Development of tuberculation is remarkably like that of Plesiotexanites,

especially P. matsumotoi sp. nov., but in this latter species the ventrolateral

tubercles remain undivided up to larger diameters, and the lateral (2) tubercle

develops more strongly. Furthermore, P. matsumotoi is distinctly unicarinate,

being a true texanitid. It would, however, be easy to derive Reginaites reymenti

from P. matsumotoi by elongation of the external tubercles to form the lateral

keels of Reginaites. The variable development of the lateral tubercle is another

feature reminiscent of Plesiotexanites, as observed in P. stangeri (Baily).

Reginaites zulu sp. nov. (described below) totally lacks development of the

lateral tubercles and remains bituberculate to a much greater diameter.

Reginaites leei (Reeside) is imperfectly known, but appears to have weaker

ornament. Reyment (1957: 66) states R. /eei to have lateral tubercles, although

Reeside (1927: 40) does not mention any.

Reginaites quadrituberculatum Reyment, here shown as Figures 87C, 89,

has similar ornament on the inner whorls, but has a more compressed whorl

section.

Reginaites durhami Young has a whorl section much higher than wide

throughout, as has Reginaites gappi Wiedmann.

Occurrence

Probably Upper Santonian or Lower Campanian of Zululand.

Reginaites zulu sp. nov.

Figs 90-92, 93A-B, 94

Holotype

SAS-H126A/9 (Figs 90A-B, 91-92, 93A-B), Bed 1 locality 105, south-

eastern shores of False Bay, Zululand, St Lucia Formation, Upper Santonian.

117

CRETACEOUS FAUNAS FROM SOUTH AFRICA

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-SVS odAjyered pure “6/V9Z7IH-SVS ‘odAjojoy 9y} JO Sase}s SAISSoOONS JO UOT}OES [IOUM “WY “AOU “ds mjNZ saywUIsay °06 ‘3A

eS q

Ol 0

118 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 91. Reginaites zulu sp. nov. Holotype SAS-H126A/9. x 1.

Etymology

Named after the original inhabitants of Zululand.

Material

Paratype is a single body chamber fragment, SAS—H126A/4 from the same

locality and horizon as the holotype, and possibly belongs to the same specimen.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 119

Dimensions

D Wb Wh Wb: Wh U

H126A/9 140,0 38,7(27,6) 40,0(28,6) 0,96 74,0(52,9)

Description

Coiling is very evolute, with an umbilical width of 52 per cent. The whorl

section varies during ontogeny, changing from subrectangular, higher than wide

on the inner whorls, through subsquare with a fastigiate venter in the late

phragmocone to distinctly higher than wide on the body chamber (Fig. 90A).

The innermost whorls are not preserved, but at a diameter of c. 55 mm,

ornament consists of a row of conical umbilical (1) tubercles connected by low,

broad, prorsiradiate ribs to bullate, slightly spirally elongated ventrolateral

(3-++4) nodes. The venter is distinctly tricarinate, with the central keel strongest.

At a diameter of c. 65 mm the ventrolateral (3-+-4) node starts showing signs

of division by the formation of a clavate node (4) on the ventral side. With

increasing diameter the separation becomes progressively more obvious, and

simultaneously, ornament in general becomes weaker, and the venter distinctly

fastigiate, as seen at the largest diameter preserved on the holotype. No sign of

lateral (2) tubercles is present at this diameter, and it is assumed that they are

absent throughout. Rib density is nineteen per whorl.

A large body chamber fragment, SAS-H126A/4 (Fig. 94A—B) from the

same locality and horizon as the holotype, has a distinct tricarinate keel, and is

here regarded as representing the adult stage of the species. The whorl section

is distinctly higher than wide, and, barring a few faint, broad undulations on

the flanks, devoid of lateral ornament.

The suture line is simple, with a long, narrow, bifid asymmetrically lateral

lobe (L.) (Fig. 90B).

Discussion

This species is identified by the apparent lack of a lateral (2) tubercle

throughout, presence of a distinctly fastigiate venter in later stages of growth,

and loss of ornament on the body chamber.

Reginaites zulu is allied to R. reymenti sp. nov. in earlier stages of growth,

but differs in later stages of growth in whorl section and ornament.

R. durhami is superficially similar in becoming less strongly ornamented in

later stages of growth, but has a distinct lateral tubercle on the phragmocone.

The ontogenetic change in ornament and whorl section of R. zulu sp. nov.

is analogous to that of some species of Yabeiceras, e.g. Y. orientale (Matsumoto

et al. 1964: 326, fig. 2a—e).

The fastigiate venter on the late phragmocone and the early bituberculate

ornament of R. zulu is very much like that of Neogauthiericeras zafimahovai

Collignon from the basal Campanian of Madagascar. It could be argued that

through retention of the bituberculate stage throughout, and earlier acquisition

of a fastigiate venter and loss of the lateral keels, R. zulu could give rise to

120 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 92. Reginaites zulu sp. nov. Holotype SAS-H126A/9. xX 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 121

Fig. 93. A-B. Reginaites zulu sp. nov. Holotype with part of phragmocone

added (also shown in Fig. 92C). C. Reginaites? sp. nov.? cf. Plesiotexanites

stangeri (Baily, 1855). x 1.

122 ANNALS OF THE SOUTH AFRICAN MUSEUM

N. zafimahovai. The respective stratigraphic occurrences of the two species

(Upper Santonian and basal Campanian) favour this relationship, but additional

material is needed to confirm it.

Occurrence

Upper Santonian of Zululand.

Reginaites ? sp. nov.? cf. Plesiotexanites stangeri (Baily, 1855)

Fig. 93C

Material

SAM-5687 and SAM-K5546, both from Bed 7 locality 1, Umzamba

Estuary, Pondoland, Transkei, Umzamba Formation, Upper Santonian.

Description and discussion

Parts of two whorls, probably belonging to the same individual, are of

special interest in that they agree with the general ornament of P. stangeri in

all respects, apart from the fact that the venter is definitely tricarinate. On the

smaller specimen, SAM-5687, the venter is preserved partially as an internal

cast, and partially with the shell preserved (Fig. 93C). In both examples the

lateral keels are continuous. On the larger fragment, SAM-—K5546, which is

part of a body chamber, the dorsum bears a distinct tricarinate impression of

the previous whorl. The venter, unfortunately, is badly damaged and deformed.

Part of a lateral keel is preserved at the proximal end, but this shows an undula-

tion which may possibly be interpreted as a wavy lateral keel.

The present material is insufficient for erection of a new species, if it is,

indeed, a representative of Reginaites.

The specimen occurs in the same horizon as that of P. stangeri in Pondo-

land, thus it does not seem possible to derive the species directly from P. stangeri.

In this connection, however, it should be borne in mind that P. stangeri already

occurs as early as Mid-Santonian in Madagascar (Collignon 1966a: 62, pl. 479

(fig. 1951)) and Lower Santonian of the Gulf Coast Cretaceous (Young 1963).

It is interesting to note that the specimen figured by Collignon (1966a: 62, pl. 479

(fig. 1951)) has very elongated external tubercles, from which the present speci-

men may be derived.

Ornament of the present specimen is not compatible with that of the other

known southern African species of Reginaites, or with P. matsumotoi, from

which the latter are supposedly derived. If the specimen is, indeed, a true

representative of Reginaites, it would seem to suggest that Reginaites is repre-

sented by two distinct, apparently independent lineages in southern Africa

(Fig. 266).

Occurrence

Upper Santonian of Pondoland, Transkei.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 123

Fig. 94. Reginaites zulu sp. nov. Paratype SAS—H126A/4. Part of the body chamber. x 0,8.

124 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Texanites Spath, 1932

Type species

Ammonites texanus Roemer, 1852, by the original designation of Spath

(1932: 379 footnote).

Diagnosis

Size of shell variable; may grow to enormous size. Coiling evolute to

involute. Ornament consists from a relatively early stage of five rows of tubercles,

with the lateral (2) row appearing last in ontogeny. Ornament is generally

variable.

Discussion

In terms of numbers, the genus Texanites is the most important texani-

tine taxon in the Upper Cretaceous deposits of southern Africa. Specimens

referred to this genus display a bewildering array of intraspecific variation,

which causes one to cast serious doubt on current texanitid systematics.

In his review of the genus, Matsumoto (1970: 270) listed the following

species definitely referable to Texanites:

Texanites dichotomus Collignon (1948: 80, pl. 9(3) (fig. 3—-3b), pl. 11(5) (fig. 1-1b))

from the Upper Santonian of Madagascar.

Texanites gallicus Collignon (1948: 75, pl. 8(2) (fig. 1—-1a), text-fig. 9) from the

Santonian of Madagascar, South America, and Europe.

Texanites hispanicus Collignon (1948: 76, pl. 8(2) (fig. 2-2b), text-fig. 11-1 1a)

from the Santonian of Spain and Madagascar.

Texanites hourcgi Collignon (1948: 78, pl. 7(1) (fig. 1-1b), pl. 10(4) (fig. 1-1a))

from the Middle Santonian of Madagascar.

Texanites interpositus Collignon (1948: 82, pl. 7(1) (fig. 3), pl. 11(5) (fig. 2)) from

the Upper Santonian of Madagascar.

Texanites pseudotexanus (de Grossouvre) (1894: 84) from the Santonian of

Germany and Bohemia.

Texanites quinquenodosus (Redtenbacher) (1873: 108, pl. 24 (fig. 3a—b)) from

the Santonian of Austria, France, Madagascar, and Angola, and tentatively

from Hokkaido.

Texanites roemeri (Yabe & Shimizu) (1923: 2) from the Santonian of Texas.

Texanites texanus (Roemer) (1852: 31, pl. 3 (fig. la—c) non fig. le-d = T. roemeri

Yabe & Shimizu) from the Santonian of North America and north Africa.

Texanites venustus Collignon (1948: 81, pl. 9(3) (fig. 4-4b)) from the Upper

Santonian of Madagascar.

In addition to these definite contenders, a number of species based on

incomplete material, generally lacking the inner whorls, were referred to the

genus:

Texanites americanus (Lasswitz) (1904: 32, pl. 8 (fig. 1)) from the Lower to

Middle Santonian of the Gulf Coast.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 125

Texanites lonsdalei Young (1963: 90, pl. 34 (fig. 1), pl. 51 (figs 3-7), pl. 58

(figs 5-6), text-fig. 22a—d) from the Lower Campanian of Texas and

Madagascar.

Texanites mikobokensis Collignon (1966a: 122, pl. 507 (fig. 2019), pl. 519

(fig. 2019)) from the Upper Santonian of Madagascar.

Texanites oliveti (Blanckenhorn) (1905: 104) from the Santonian of the Middle

East.

Texanites quadrangulatus Collignon (1966a: 76, pl. 486 (fig. 1961)) from the

Upper Santonian of Madagascar.

Texanites rarecostus Collignon (1966a: 78, pl. 487 (fig. 1965)) from the Middle

Santonian of Madagascar.

To this list of doubtful contenders may be added:

Texanites angolanus Haas (1942: 12, figs 8-10, 11) from the Santonian of

Angola.

Texanites omeraense (Reeside) (1927: 38, pl. 42 (figs 3-4), pl. 43 (figs 1-2)) from

the Santonian of the Western Interior of North America.

Texanites ralijaonai Collignon (1966a: 130, pl. 511 (fig. 2023)) from the San-

tonian of Madagascar.

New species from South Africa, described below are:

Texanites collignoni sp. nov.

Texanites postvanhoepeni sp. nov.

Texanites presoutoni sp. nov.

Texanites umzambiense sp. nov.

Texanites vanhoepeni sp. nov.

In addition to displaying tremendous intraspecific variation, the Zululand

Texanites species connect with Paratexanites and Submortoniceras.

Texanites collignoni may be derived from Plesiotexanites collignoniforme

sp. nov., which in turn has its origin in Paratexanites. Texanites soutoni 1s

derived, probably through 7. presoutoni sp. nov., from T. umzambiense sp. nov.,

which is closely allied to, though apparently slightly younger than, Plesio-

texanites collignoniforme sp. nov. Texanites quadrangulatus and T. rarecostus

appear to connect with Paratexanites, without passing through a Plesiotexanites

stage, via Texanites vanhoepeni sp. nov., the latter probably derived from Para-

texanites umkwelanensis.

Texanites soutoni gradually gives rise to Submortoniceras towards the

Santonian/Campanian boundary, and Texanites vanhoepeni and T. postvan-

hoepeni also show a distinct tendency towards acquisition of Submortoniceras

characteristics in stratigraphically younger strata. This takes place through a

gradual decrease in umbilical width and loss of lateral ornament. Details are

given in the descriptions of the species. Similar trends are shown by Texanites

shiloensis and Submortoniceras tequesquitense from the Gulf Coast of North

America, which may possibly represent a geographically separated relative of

the species group of Texanites soutoni and Submortoniceras woodsi.

126 ANNALS OF THE SOUTH AFRICAN MUSEUM

The latter species group also shows what appears to be a distinct geographic

differentiation into two groups inhabiting the deep and shallow waters of the

St Lucia Formation and Umzamba Formation respectively.

Texanites is distinguished from Plesiotexanites by virtue of the early

development of the pentatuberculate stage, although, in cases such as T. umzam-

biense sp. nov. and P. collignoniforme sp. nov., the distinction between the two

taxa becomes subjective. None the less, Plesiotexanites should be maintained

separate from Texanites as a distinctive group which provides the source for

Reginaites and, in some cases, Texanites.

In large phragmocone or body chamber fragments it is impossible to

distinguish between Texanites and Plesiotexanites, unless the ventrolateral

tubercles are approximated in Paratexanites fashion.

As mentioned above, differences between Texanites and Submortoniceras

are gradual, hence allocation of border-line cases such as 7. soutoni to either

of the genera becomes a matter of opinion, depending on where to draw the

line between Texanites and Submortoniceras.

Texanites collignoni sp. nov.

Figs 95, 96A, 97-98, 99B-C, 100-101

Texanites oliveti non Blanckenhorn: Collignon, 1948: 72, pl. 8(2) (figs 3-5), text-figs 5-8.

Texanites oliveti non Blanckenhorn var. spinosa Collignon, 1966a: 68, pl. 482 (fig. 1955).

?Texanites oliveti (Blanckenhorn): Matsumoto & Ueda 1962: 169, pl. 26 (fig. 2), text-fig. 13.

Holotype

SAM-PCZ5920 (Fig. 98), locality 74, north-western part of Die Rooiwalle,

Zululand, St Lucia Formation, Santonian I-II.

Etymology

Named after the late General Maurice Collignon, Moirans, France.

Material

Paratypes are SAS—H179/19, locality 6, excavations in the Enseleni Reserve,

Zululand, St Lucia Formation, Santonian II-III; SAS—Z866, Z1754, Z1755,

BMNH-C81551—C81558, locality 74, north-western part of False Bay at

Die Rooiwalle, Zululand, St Lucia Formation, Santonian I-II; SAS-—Z351,

from an unknown locality near Mfolozi, probably locality 14, St Lucia Forma-

tion, Santonian II to Campanian I; BMNH-C81507—C81508, from foreshore

exposures west of Lister’s Point, Zululand, St Lucia Formation, Santonian I-II;

BMNH-C81515, from foreshore exposures north of Picnic Point, St Lucia

Formation, Santonian I-II; a body chamber fragment NMB-D1353, locality 73,

St Lucia Formation, Santonian I, may also be referred to this species; SAM-—

PCZ5711, labelled ‘S.A. Cretaceous’ also belongs to the species, and, judging

by the matrix, this specimen may have been collected in the vicinity of locality 74

at Die Rooiwalle.

127

CRETACEOUS FAUNAS FROM SOUTH AFRICA

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JJOUM ‘@ ‘SOIOW[IUT UT oINyNS IOJ Ieq BJeOG “SSLTZ-SVS odAyered Jo oul] omNyNg “y “AOU “ds juoUsIjOI SajtuDxXAaT °C6 “SI

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128 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

H179/19 — 31,6 43,0 0,73

Z866 255,0 66,0(29,3) 86,0(33,7) 0,77 116,0(45,5) 32 32

Z1754 257,0 59,0(22,9) 89,0(34,6) 0,66 117,0(45,5) Mil 33

Z351 213,0 51,0(23,9) 66,0(30,9) 0,77 106,0(49,8) 32 32

FAAS 230,0 56,5(24,6) 79,0(34,3) 0,72 99,0(43,0) —_— es

Description

Coiling is evolute, with an umbilical width varying between 43 and 49 per

cent of the diameter, but usually of the order of 45 per cent. Whorl overlap is

minimal, and the dorsal zone of impression consequently small.

The whorl section in all the available specimens is higher than wide through-

out, but differs in details from one specimen to another, and also throughout

ontogeny (Fig. 95B, 96A). The umbilical wall is virtually vertical on the inner

whorls, but becomes rounded on the outer whorls, merging gently into the

gently inflated flanks. The flanks converge gradually to a rounded venter,

narrower than the dorsum. In intercostal section maximum width is towards

Fig. 96. A. Texanites collignoni sp. nov. Whorl section of paratype

SAS-Z1755. B. Uncorrected sketches of whorl section of Texanites

oliveti (Blanckenhorn, 1905) from Israel. x 0,5.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 129

the dorsal third of the flanks, coinciding with the position of the lateral tubercle.

None of the specimens has the innermost whorls preserved, and the earliest

whorls preserved already show pentatuberculate ornament.

Typical ornament, as shown by SAS—Z866 (Fig. 97) and SAM—PCZ5920

(Fig. 98), consists of radial to slightly rursiradiate single ribs, each bearing a

rounded to radially elongated umbilical (1) tubercle, displaced slightly ventrally

Fig. 97. Texanites collignoni sp. nov. Paratype SAS-—Z866. x 0,58.

130 ANNALS OF THE SOUTH AFRICAN MUSEUM

from the umbilical edge, a prominent radially elongated, lateral (2) tubercle

towards the dorsal third of the flanks (this tubercle juts out furthest laterally

though it is not necessarily strongest developed), and progressively clavate

submarginal (3), marginal (4) and external (5) tubercles over the rest of the

flanks. With increasing diameter, and especially towards the body chamber,

the umbilical and the lateral tubercles move ventrally, so that the former is

some distance from the umbilical region and the latter nearer midflank. In

typical forms ribbing is single, but some specimens feature bifurcations. The

keel is undulating; undulations coinciding with lateral ornament.

Fig. 98. Texanites collignoni sp. nov. Holotype SAM-—PCZ5920. x 0,5.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 131

Fig. 99. A. Texanites oliveti (Blanckenhorn, 1905). Specimen from Judean desert. (Photo-

graph Z. Lewy.) B-—C. Texanites collignoni sp. nov. Paratype SAS—H179/19. This specimen

remains rectangular to a large diameter. x 1.

132 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 100. Texanites collignoni sp. nov. Paratype SAS-Z1754. x 0,5.

Discussion

This species is common in the Lower Santonian of Zululand, and the

authors (Kennedy & Klinger 1975: 279) initially identified it with Texanites

oliveti (Blanckenhorn). Texanites oliveti, however, is a very poorly known

species, as the figures provided by Taubenhaus (1920: 30, pl. 5 (figs 3, 5)) are

very much reduced. According to Blanckenhorn (1905: 104) the species is

identified by: 26 to 28 strong ribs, slightly narrower than the interspaces,

simple, single, radial and slightly forwardly curved on the ventral third of the

CRETACEOUS FAUNAS FROM SOUTH AFRICA 133

flanks. The undulations on the keel correspond with the ribs. The ribs bear

five rows of tubercles. . . . The umbilical tubercles and the two outer rows are

strongest developed, while the second (lateral) row is always poorest developed.

(Authors’ free translation.)

This description fits the material rather well, but Z. Lewy (pers. comm.

1979) has informed the authors that, according to material from Israel, T. oliveti

is a typically compressed form, with Wb : Wh ratio being of the order of 0,4 to

0,5 and seems to occur in the Upper Santonian only. A typical specimen from the

Judean desert is here figured as Figure 99A, and whorl sections of other Israeli

material as Figure 96B. Apart from the fact, thus, that the Zululand and Mala-

gasy specimens are older than typical T. oliveti, they are also much more inflated,

with Wb : Wh ratios of the order of 0,7. It seems advisable to refer the Zululand

and Malagasy material to a new species, JT. collignoni sp. nov., to separate it

from the younger, more compressed 7. oliveti. The specimen from the Lower

Santonian of the Himenoura Group described by Matsumoto & Ueda (1962:

170) as Texanites oliveti (Blanckenhorn) also probably belongs to this species.

Collignon (1948: 72-75) discussed T. collignoni (as T. oliveti) at length,

although his material consisted of small fragments only. Apart from the typical

form, which has a more or less rectangular section, Collignon recognized two

other varieties, var. spinosa and var. triangularis. Var. spinosa has more or less

the same whorl section as the typical form, but differs in that the tubercles of

the first three rows are rounded, and so strong that the intertubercular areas

are as deep as the intercostal spaces. In var. triangularis the ornament is essen-

tially the same as in the typical form, but the section is triangular.

As far as tuberculation is concerned, the Zululand material compares

well with Collignon’s descriptions and figures of the Malagasy material; as far

as whorl section is concerned, the Zululand specimens are somewhat different

in having a steeper or more rounded umbilical wall. The more complete Zulu-

land specimens show that whorl section changes during growth, starting with

rectangular section on the inner whorls, eventually becoming subrectangular

to ovoid on the later parts of the phragmocone and body chamber. One of the

specimens, however, SAS—H179/19 (Fig. 99B) retains the rectangular whorl

section to a greater diameter than the other specimens.

In most of the specimens ribbing is single on the outer whorls. In SAS-

Z1754 (Fig. 100), however, bifurcations are quite common on the outer whorls.

Apart from being more compressed than the other specimens, there seems to be

no other significant difference, and the specimen is also referred to T. collignoni

sp. nov. It appears to connect morphologically with T. soutoni, described below.

Differences between T. collignoni and T. texanus are distinct in density

of ribbing in typical forms, but become obscure when comparing T. collignoni

with T. texanus var. hispanica. Here crenulation of the keel may be of assistance

in differentiating between the species.

T. quinquenodosus (Figs 102-103) is a species with similar ribbing and

coiling, but differs in that tuberculation is generally clavate in all the rows.

ANNALS OF THE SOUTH AFRICAN MUSEUM

134

Paratype SAS-Z1755. x 0,6.

i sp. NOV.

ignoni

Texanites coll

ig. 101.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 135

Even though all Redtenbacher’s (1873) specimens were crushed, it appears as

though the whorl section is more compressed than in T. collignoni. This raises

the possibility that T. oliveti may be a junior synonym of T. quinquenodosus.

The rounded umbilical wall, ventrally displaced umbilical tubercle, and

undulating keel in T. collignoni are very similar to Plesiotexanites collignoniforme

sp. nov. described above (p. 89), and it seems reasonable to derive T. col-

lignoni from that species.

Schloenbachia (Mortoniceras) sandreczkii Blanckenhorn (1905: 105) may

be allied, but is difficult to interpret. In this species only the external row of

tubercles is developed, and it seems closer to Submortoniceras than Texanites.

Schloenbachia (Mortoniceras) safedensis Blanckenhorn (1905: 106) is

another enigmatic species and may possibly represent a compressed specimen of

T. oliveti or a closely allied species.

Occurrence

Lower and Middle Santonian of Madagascar, Santonian I-II of Zululand,

Lower Santonian of Japan.

[While this article was in press, a publication by Matsumoto & Haraguchi

(Matsumoto, T. & Haraguchi, Y. 1978. A new Texanitine Ammonite from

Hokkaido. Trans. Proc. Palaeont. Soc. Japan, N.S. 110: 306-318) which has

bearing on the discussion of Texanites oliveti, came to the notice of the authors.

Matsumoto & Haraguchi suggest that Texanites oliveti is a good index species

for the Lower Santonian, but also express doubt whether the specimensdescribed

by Collignon from Madagascar are, indeed, conspecific with the Middle East

specimens of 7. oliveti, and whether the latter is distinguishable from T. quin-

quenodosus. In view of our current knowledge and interpretation of Texanites

oliveti, it is not a suitable index species for the Lower Santonian.

Pop & Szasz (Pop, G. & Szasz, L. 1973. Santonianul din Reguinea Hategului

(Carpatii meridionali). St. cerc. geol., geofiz., geogr., Ser. geologie 18: 463-467)

also described and figured a specimen as Texanites oliveti from Bulgaria, which

seems identifiable with T. collignoni.]

Texanites quinquenodosus (Redtenbacher, 1873)

Figs 102-103

Ammonites texanus Roemer: von Hauer, 1858: 10, pl. 2 (figs 4-6).

Ammonites quinquenodosus Redtenbacher, 1873: 108(18), pl. 24 (fig. 3a—b).

Mortoniceras texanus (Roemer): Ziircher, 1903: 686.

Mortoniceras quinquenodosus (Redtenbacher): Yabe & Shimizu, 1923: 30.

Texanites quinquenodosus (Redtenbacher): Collignon, 1948: 69(24), text-fig. 2; 1966a: 128,

pl. 510 (fig. 2021). Matsumoto 1970: 272. Thomel, 1969: 12(120).

Discussion

A full review of this species, based on all the original type material,

is in preparation by the authors. One of the syntypes, now housed in the

136 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 102. Texanites quinquenodosus (Redtenbacher, 1873). Plaster cast of

one of Redtenbacher’s syntypes from the Oberésterreichisches Landes-

museum, Linz. x 0,65.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 137

Fig. 103. Texanites quinquenodosus (Redtenbacher, 1873). Plaster cast of one of Redten-

bacher’s syntypes from the Oberdsterreichisches Landesmuseum, Linz. x 0,65.

138 ANNALS OF THE SOUTH AFRICAN MUSEUM

Oberosterreichisches Landesmuseum, Linz (Austria), is here figured photo-

graphically (Figs 102-103) for comparison with the South African material.

Texanites quadrangulatus Collignon, 1966

Figs 104-108

Texanites quadrangulatus Collignon, 1966a: 76, pl. 486 (fig. 1961).

Holotype

The specimen figured by Collignon (1966a, pl. 486 (fig. 1961)) from the

Upper Santonian of Madagascar, Zone of Pseudoschloenbachia umbulazi.

Material

SAS-A2580, SAS-—Z1760, SAM-—PCZ5879-PCZ5882, BMNH-C81513-

C81514, all from locality 74, False Bay, Zululand, St Lucia Formation, San-

tonian I to Campanian I; SAS-H179/18, locality 6, Enseleni Reserve, Zululand,

St Lucia Formation, Santonian II to Campanian I; SAS—Z595, locality 14,

Mfolozi, Zululand, St Lucia Formation, Santonian IJ-IIJ; BMNH-C81511,

locality 84, False Bay, St Lucia Formation, Santonian I.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

H179/18 — 27,0 27,0 1,0 — = —

PCZ5879 125,0 48,0(38,4) 51,0(40,8) 0,94 46,0(36,8) 11x2 —

PCZ5880 142,0 54,0(38,0) 54,0(38,0) 1,0 58,0(40,8) 25 26

Z1760 175,0 65,0(37,1) 71,0(40,6) 0,91 61,0(34,9) 13x2 —

A2580 245,0 76,0(31,0) 93,0(38,0) 0,82 93,0(38,0) 29 29

Holotype

after

Collignon

1966a: 76 145,0 50,0(34,0) 50,0(34,0) 1,0 59,0(41,0) — ?30

Description

Coiling is relatively evolute, with an umbilical diameter of 35 to 41 per cent

of the total diameter. Whorl overlap is minimal with the marginal (4) tubercles

clearly exposed in the umbilical seam. Increase in diameter is rapid.

The costal whorl section on the phragmocone is distinctly quadrate,

sometimes even wider than high in early stages, whereas the intercostal section

is more rounded (Figs 106B, 108). Towards the later part of the phragmocone

the whorl section becomes more rounded (Fig. 107B), higher than wide, and

eventually dome-shaped on the body chamber (Fig. 105A). Ornament on the

phragmocone consists of prominent ribs bearing very strong tubercles and

separated by wider interspaces. The umbilical (1) tubercles are conical to

radially elongated, pointed slightly inwards and with bases extending a

little distance down the umbilical wall. The lateral (2) tubercles are situated

at midflank or on the dorsal third of the flanks and are conical to clavate, and

separated from the umbilical tubercles by a depression on the ribs. The sub-

marginal (3), marginal (4), and external (5) tubercles are situated closer to each

CRETACEOUS FAUNAS FROM SOUTH AFRICA 139

Fig. 104. Texanites quadrangulatus Collignon, 1966. SAS-A2580. x 0,58.

other than the umbilical and lateral ones throughout ontogeny, but especially

on the inner whorls. Here the submarginal tubercles may be tremendously

enlarged and partially fused to the marginal tubercles, having the appearance

of Paratexanites. The external (5) tubercles are very clavate and generally as

high as, or higher than, the central keel. Bifurcations occur, but not frequently.

Towards the later part of the phragmocone and the body chamber, all ornament

becomes subdued (Fig. 104).

ANNALS OF THE SOUTH AFRICAN MUSEUM

140

ipa,

MO map yy

1966. SAS-A2580. x 0,58.

ignon,

105. Texanites quadrangulatus Coll

ig.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 141

Fig. 106. Texanites quadrangulatus Coliignon, 1966. SAM-PCZ5881. Suture line, x 5.

Whorl section, x 1.

The external suture comprises a blocky, wide E/L saddle, narrow L/U2

saddle and long, narrow lateral lobe (L), somewhat restricted towards the top

(Fig. 106A).

Discussion

The quadrate whorl section on the greater part of the phragmocone,

strong ornament and, depending on preservation, strong development of the

submarginal tubercle and Paratexanites-like spacing of the submarginal (3),

ANNALS OF THE SOUTH AFRICAN MUSEUM

142

TX “6LESZOU-INVS “9961 “WOUsTTIOD smnjnSuviponb sayuoxaL

“LOL ‘Std

143

CRETACEOUS FAUNAS FROM SOUTH AFRICA

TV Wy

SAM-PCZ5881.

. A-B

1966

ignon

Texanites quadrangulatus Colli

108

Fig.

C-E. SAS-H179/18. x 1.

144 ANNALS OF THE SOUTH AFRICAN MUSEUM

marginal (4), and external (5) tubercles are all characteristic of the species.

T. vanhoepeni is a similar, though older, species. Here, however, the rate

of increase of diameter is greater than in 7. quadrangulatus, the whorl section

is more rounded in the adult stage, and it lacks the strong ornament.

Matsumoto (1970: 272) speculated on the origin of 7. quadrangulatus,

suggesting that it could be derived from Protexanites bourgeoisi or Paratexanites

serratomarginatus grossouvrel.

Present material suggests that it would seem more feasible to derive

T. quadrangulatus from Paratexanites pseudotricarinatum or P. umkwelanense,

possibly via 7. vanhoepeni.

Occurrence

Middle and Upper Santonian of Madagascar and Zululand.

Texanites vanhoepeni sp. nov.

Figs 109-117

Holotype

SAS-Z879 (Figs 109-110), locality 83, foreshore exposures at Mason’s

Camp, south-western part of False Bay, Zululand, St Lucia Formation, Coni-

acian IV.

Etymology

Named for the late Dr E. C. N. van Hoepen.

Material

Paratypes are SAS—Z1792, Z2110, H201/33, and BMNH-C81534—-C81535,

locality 84, beach exposures in the south-western part of False Bay, Zululand,

St Lucia Formation, Santonian I; BMNH-—C81509—-C81510, C81521, C81537,

locality 85, Santonian I; SAS—H200/92 from the same horizon and locality as

the holotype; NMB-D1364 and D1379, from the same region at locality 86,

St Lucia Formation, Coniacian V to Santonian I or II; NMB—D1353, locality 73,

the lower reaches of the Mzinene River, St Lucia Formation, Coniacian to

Santonian; and BMNH-C81559, locality 74, St Lucia Formation, Santonian

I-II.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

Z879 183,0 69,0(37,7) 71,0(38,8) 0,97 70,0(38,2) 24 24

H200/92 192,0 _ 67,0(34,9) — 79,0(41,1) 28 28

Description

Coiling is evolute, with rapidly increasing whorls (Figs 111-112). The

whorl section is more or less equidimensional throughout, but changes from

subquadrate to rounded during growth, especially at the umbilical edges

(Fig. 113A).

CRETACEOUS FAUNAS FROM SOUTH AFRICA 145

Fig. 109. Texanites vanhoepeni sp. nov. Holotype, SAS-Z879. x 0,86.

146 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 110. Texanites vanhoepeni sp. nov. Holotype, SAS-Z879. x 0,8.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 147

Fig. 111. Texanites vanhoepeni sp. nov. Paratype SAS-H201/33. x 1.

None of the specimens has the very innermost whorls preserved to show

the ontogeny. Ornament on the phragmocone consists of sparse, single radial

ribs bearing prominent tubercles. Rib density is generally of the order of 24,

but may be as high as 28. The umbilical (1) tubercles are radially elongated,

pointing slightly inwards. The lateral (2) tubercles at the dorsal third of the

flanks are usually very prominent and conical to slightly clavate. The submargi-

nal (3) at the ventral third of the flanks is clavate and generally smallest.

148 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 112. Texanites vanhoepeni sp. nov. Paratype SAS—H201/33. x 1.

The marginal (4) and external (5) tubercles are very clavate, and, in some

ases, situated closer to each other than the submarginal (3) and marginal (4).

These former tubercles may be strongly developed, and protrude far above the

venter.

The keel is very low and poorly developed, but distinctly undulating, in

some cases forming a row of weakly clavate tubercles along the siphonal line

corresponding in location to the ribs.

The suture has a very long and thin lateral lobe (L) (Fig. 113B).

CRETACEOUS FAUNAS FROM SOUTH AFRICA 149

ao =-

Fig. 113. Texanites vanhoepeni sp. nov. A. Whorl section of para-

type SAS—H201/33. B. Partial suture line of paratype SAS—Z2111. x 1.

150 ANNALS OF THE SOUTH AFRICAN MUSEUM

On the body chamber ornament remains prominent, but becomes wider

spaced (Figs 114-115).

Discussion

This species is easily distinguished by the rapid increase in whorl diameter,

generally sparse costation and undulating keel.

Unfortunately, the available material of this species is limited, and accurate

stratigraphic data scant. There does, however, seem to be a tendency towards

Fig. 114. Texanites vanhoepeni sp. nov. Paratype NMB-D1364. Specimen illustrating wider

spacing of ornament towards and on body chamber. x 0,5.

151

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Body chamber fragment.

,66

Paratype NMB-D1379

x 0

Fig. 115. Texanites vanhoepeni sp. nov.

152 ANNALS OF THE SOUTH AFRICAN MUSEUM

tighter coiling higher up in the sequence, giving rise to a Submortoniceras-like

form, Texanites postvanhoepeni sp. nov., described below. This tendency in

coiling is illustrated by SAS—H200/92 (Fig. 116) with widest umbilical width

at 41 per cent, through the holotype SAS—Z879 (Fig. 109) with umbilical

width of 38 per cent, to SAS—Z2100 (Fig. 117) with an umbilical diameter of

about 33 per cent.

The rounded whorl section in the adult stage, and the undulating keel

relate this species to Texanites collignoni, Plesiotexanites collignoniforme, Para-

texanites umkwelanense and P. pseudotricarinatum. Stratigraphic data seem to

suggest that 7. vanhoepeni may be derived from P. umkwelanense, or some

common ancestral form. Apart from the lateral tubercle, the whorl section of

the two species is remarkably alike, as is the prominence of the marginal (4)

and external (5) tubercles in cases.

Unfortunately, the very innermost whorls are not preserved, but at a

— a

Fig. 116. Texanites vanhoepeni sp. nov. Paratype SAS—H200/92. Specimen

with greatest umbilical width. x 0,55.

153

CRETACEOUS FAUNAS FROM SOUTH AFRICA

ecimen with smallest

width. x 1

Paratype SAS-Z2110

]

lica

p. nov

umbi

Texanites vanhoepen

Fig. 117.

154 ANNALS OF THE SOUTH AFRICAN MUSEUM

diameter of 45 mm lateral tubercles are already present, indicating that this is

probably a Texanites and not referable to Plesiotexanites. This suggests that in

this case Texanites s.s. was derived directly from Paratexanites without a Plesio-

texanites stage as in the case of T. collignoni (p. 126).

Texanites collignoni differs in having a completely different whorl section

and much slower expanding whorls, as does Plesiotexanites collignoniforme.

As far as lateral ornament is concerned, there is close resemblance to

Texanites ralijaonai from the Upper Santonian of Bevaho (Belo sur Tsiribihina),

Madagascar. In that species, however, increase in whorl diameter is not as

rapid as in the present species as Collignon’s (1966a: pl. 512 (fig. 2023)) figure

shows. That species also lacks an undulating keel.

Texanites rarecostus Collignon from Zululand and Madagascar has similar

sparse costation, c. 23-24 per whorl, but has less massive whorls and a very

slow rate of whorl increase.

Texanites quadrangulatus has proportions and ornament which overlaps

with that of the present species to a certain extent, and it is possible that they

are genetically related. 7. quadrangulatus, however, generally has less massive

whorls, a slower increase in diameter, a smaller lateral tubercle and has the

three ventral rows approximated.

Occurrence

Upper Coniacian to Lower Santonian of Zululand.

Texanites postvanhoepeni sp. nov.

Figs 118-120

Holotype

SAM-PCZ5902 (Fig. 118), locality 85 or 86, foreshore exposures at Mason’s

Camp, south-western part of False Bay, Zululand, St Lucia Formation, Coni-

acian V to Santonian I and II.

Etymology

Refers to possible derivation from Texanites vanhoepeni.

Material

SAS-Z1787 and BMNH-C81522 from the same locality and horizon as the

holotype.

Dimensions

D Wb Wh Wb: Wh Of Int. Ext.

PCZ5902 182,0 68,0(38,2) 80,0(43,9) 0,85 59,0(32,4) 20 32

Z1787 220,0 84,0(38,2) 96,0(43,6) 0,87 67,0(30,4) — —

Description

Coiling is involute, with an umbilical width of 30 to 32 per cent, and very

rapidly increasing whorls. The dorsal zone of impression, however, is very

CRETACEOUS FAUNAS FROM SOUTH AFRICA 155

shallow, and successive whorls cover each other only up to the middle of the

marginal (4) tubercle.

The whorl section throughout, as far as visible, is higher than wide, with

an overhanging to vertical umbilical wall, flanks parallel up to the lateral (2)

tubercle, which marks the greatest width, and then converging slowly to the

marginal (4) and eventually the external (5) tubercle (Fig. 120A).

On the innermost whorls preserved, ribs bifurcate quite frequently. Small,

Fig. 118. Texanites postvanhoepeni sp. nov. Holotype SAM—PCZ5902. x 0,67.

156 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 119. Texanites postvanhoepeni sp. nov. Paratype SAS—Z1787. x 0,67.

conical umbilical (1), *lateral (2), submarginal (3), and clavate marginal (4)

tubercles are exposed on the flanks. Beyond a diameter of c. 70 mm, all lateral

ornament weakens progressively, though never disappearing completely.

The suture is incompletely exposed, but shows a subtrifid, long and narrow

lateral lobe (L).

CRETACEOUS FAUNAS FROM SOUTH AFRICA 157

Fig. 120. Texanites postvanhoepeni sp. nov. Paratype SAS-Z1787. x 0,67.

158 ANNALS OF THE SOUTH AFRICAN MUSEUM

Discussion

As mentioned above (p. 152), this species appears to be the end member in

a series of specimens with progressively tighter coiling. Starting with an evolute

form of 7. vanhoepeni sp. nov. with an umbilical diameter of 41 per cent, it

terminates with the present species, with an umbilical width of only 30 to 32

per cent. Unfortunately precise stratigraphic data are lacking to fully confirm

this assumption, but it would be in line with the general recoiling pattern

observed in 7. soutoni and allied species (described below, p. 172). As in the

latter, the dividing line here between Texanites and Submortoniceras becomes

arbitrary. Because the holotype still has weak lateral tubercles present at the

largest diameter preserved, the species is referred to Texanites rather than

Submortoniceras.

Texanites quadrangulatus has a very similar shape, but differs mainly in

having a very prominent quadrate whorl section on the early part of the phrag-

mocone, much stronger tuberculation and a slightly wider umbilicus (34-40 %).

T. postvanhoepeni is similar to Submortoniceras woodsi, but in the latter

the whorl section is more compressed, and coiling looser.

Occurrence

Lower to Middle Santonian of Zululand.

Texanites rarecostus Collignon, 1966

Figs 121-122

Texanites rarecostus Collignon, 1966a: 78, pl. 487 (fig. 1965).

Type

Holotype by monotypy is the specimen figured by Collignon (1966a:

pl. 487 (fig. 1965)) from the Middle Santonian of Beantaly-Souromaraino,

Madagascar.

Material

SAS-Z596, locality 14, Mfolozi, Zululand, St Lucia Formation Santonian

II and III to Campanian I; and SAM-—PCZ5878 from an unknown locality,

presumably locality 74, the north-western end of False Bay, Zululand, St Lucia

Formation, Santonian to Campanian.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

Z596 120 31,0(25,8) 34,0(28,3) 0,91 5910492) 13x23 Beez

64,0 18,5(28,9) 20,0(31,3) 0,92 30,0(46,9) 13x2 13x2

PCZ5878 102 30,0(29,4) 33,0(32,4) 0,91 50,0(49,0) 11x2 11x2

Holotype

after

Collignon 128 38,0(30,0) 40,0(31,0) —0,95 62.0(48.0) 23 24

CRETACEOUS FAUNAS FROM SOUTH AFRICA 159

Description

Two incomplete specimens with part of the body chamber preserved are

tentatively referred to Collignon’s species. Coiling is very evolute with an

umbilical width of 46 to 49 per cent of the diameter. Whorl overlap is very small

with the marginal tubercles clearly exposed in the umbilical suture.

The intercostal whorl section is rounded with maximum width at midflank

A B

Fig. 121. Texanites rarecostus Collignon, 1966. SAS—Z596. A x 1,05; B x 1,3.

160 ANNALS OF THE SOUTH AFRICAN MUSEUM

or at the umbilical edge. Costal whorl section is subquadrangular, slightly

higher than wide with maximum whorl breadth at the umbilical (1) tubercle or

lateral (2) tubercle, but later migrating towards the submarginal (3) tubercle.

SAS-Z596 shows part of the early ontogeny. At a diameter of 14 mm

ornament consists of regularly bifurcating thin ribs displaying conical umbi-

lical (1) and submarginal (3) tubercles on the exposed flank. At a diameter of

c. 32 mm ribs still bifurcate regularly, rib density being about 11 (bifurcating

ribs) per half whorl. The submarginal (3) tubercles have now migrated towards

the ventral quarter or third of the exposed flanks, exposing the marginal (4)

tubercles in the umbilical suture. Lateral (2) tubercles start appearing at a

diameter of c. 40 mm, and at this stage the four exposed rows are arranged

equidistantly on the flanks. Bifurcations occur less frequently, and all ornament

coarsens, resulting in a lower rib density.

In the adult stage the umbilical (1) and lateral (2) tubercles are distinctly

conical, while the remaining three rows are clavate.

The keel is entire, and generally lower than the external tubercles. The

suture has massive saddles and a U-shaped lateral lobe (L).

Discussion

The holotype of the species consists of slightly more than a whorl and is

difficult to interpret. The Zululand specimens have comparable relative propor-

tions, but seem to have more robust ornament. In addition, SAS—Z596 has

distinctly prorsiradiate ribs on the outer whorl compared to rectiradiate on the

holotype. On the basis of the limited material available, it is not known whether

these differences are of any significance.

Differences between J. rarecostus and T. americanus are not very clear.

The outer whorl of SAS—Z596 (Fig. 121) is very similar to the holotype of

T. americanus (see Lasswitz 1904, pl. 8 (fig. 1)). The inner whorls of the holo-

type, however, are not as densely costate as those of the Zululand specimen.

Young (1963: 83-4) suggested that Lasswitz’s artist may have erred in drawing

the inner whorls of the holotype. Even Young’s material, however, is more

coarsely costate on the inner whorls (compare Young 1963: pl. 44 (fig. 2)). On

the other hand, if density of ribbing on the inner whorls of Plesiotexanites is

taken into consideration, this difference seems very trivial indeed. Of more

importance seems to be the difference in whorl section, that of 7. americanus

being more inflated than that of T. rarecostus. For the present the two species

are retained apart, in cognizance of their close resemblance.

Plesiotexanites stangeri is a similarly evolute species, but differs in the late

development of the lateral tubercle and in generally lacking the strong ornament

on the body chamber of T. rarecostus.

Small specimens of the inner whorls of T. vanhoepeni sp. nov. may be

mistaken for T. rarecostus in having a similar whorl section, but in more com-

plete material the rapid increase in size is apparent.

Another allied species is T. quadrangulatus, but in the latter the whorl

CRETACEOUS FAUNAS FROM SOUTH AFRICA

\S\

\\S

Fig. 122. Texanites rarecostus Collignon, 1966. SAM-—PCZ5878.

161

162 ANNALS OF THE SOUTH AFRICAN MUSEUM

section is more quadrate at larger diameters, and increase in size is also much

more rapid.

Occurrence

T. rarecostus occurs in the Middle Santonian of Madagascar, Zone of

Texanites hourcgi and Santonian of Zululand.

Texanites texanus s.\. (Roemer, 1852)

Figs 123-125

Texanites texanus (Roemer): Collignon, 1948 : 66(20), text-fig. 1-1b (with synonymy); 1966b: 52,

pl. 33.

Texanites texanus var. gallica Collignon, 1948: 75(30), pl. 8(2), (fig. 1-1a), text-figs 9-10.

Texanites texanus var. hispanica Collignon, 1948: 76(31), pl. 8(2) (fig. 2—2b), text-fig. 11-11a.

Texanites texanus texanus (Roemer): Young, 1963: 80, pl. 38 (figs 1-2), pl. 40 (figs 1-3), pl. 41

(fig. 4), text-figs 21g, 22e, 25d.

Texanites texanus gallica Collignon: Young, 1963: 82, pl. 38 (figs 3-4).

Texanites texanus twiningi Young, 1963: 82, pl. 38 (fig. 5), pl. 39 (fig. 1), pl. 41 (figs 2, 5), pl. 48

(fig. 4).

Texanites gallicus Collignon, 1966a: 78, pl. 487 (fig. 1964).

Texanites hispanicus Collignon, 1966a: 128, pl. 510 (fig. 2022).

Material

SAS-H139, locality 14, road cuttings near Mfolozi, Zululand, St Lucia

Formation, Santonian IJ-III to Campanian I; and an unnumbered specimen in

the offices of the Geological Survey, Cape Town, here referred to as GSO CT,

from an unspecified horizon at locality 1, Umzamba Cliff, Pondoland, Transkei,

Umzamba Formation, Santonian to Campanian.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

I T

SAS-H139 165 44,5(27,0) 57,0(34,5) 0,78 72,7(44,1) 31 33

114,2 32,8(28,7) 39,8(34,8) 0,82 48,3(42,3) 29 34

GSO CT 223,9 — 71,6(31,9) — 101,5(45,3) 36 36

(unnumbered

specimen)

Description

SAS-H139 and GSO CT are fairly complete specimens with parts of the

body chamber preserved. Coiling is evolute, with an umbilical diameter

measuring 42 to 45 per cent of the total diameter. Whorl overlap is minimal,

covering the successive whorls up to the marginal (4) tubercles. The whorl

section throughout is higher than wide, with a sub-ovoid to subrectangular

whorl section both in costal and intercostal section.

Specimen SAS—H139 has the innermost whorls preserved up to a diameter

of 7 mm. Here ornament consists of regularly bifurcating ribs with weak

umbilical, and strong ventrolateral, spines. Beyond a diameter of 7 mm ribs

bifurcate frequently with occasional single ribs. The ventrolateral row of

tubercles progressively migrates away from the umbilical wall to expose a

CRETACEOUS FAUNAS FROM SOUTH AFRICA 163

Fig. 123. Texanites texanus (Roemer, 1852). Unnumbered specimen from the Cape Town

branch of the Geological Survey. Probably referable to subspecies or variety hispanica.

164 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 124. Texanites texanus (Roemer, 1852). SAS—H139. This specimen is best referred

to subspecies or variety gallica. x 0,8.

third row of tubercles in the umbilical suture. Weak lateral (2) tubercles start

appearing at a diameter of c. 20 mm near the dorsal third of the flanks. Beyond

that diameter ornament remains more or less the same. The only significant

change is that tuberculation becomes more prominent, and bifurcations less

frequent, to eventually disappear completely on the body chamber.

The ribs are generally straight and slightly rursiradiate throughout. The

umbilical (1) tubercles are conical to radially elongated, pointing slightly

inwards. The lateral (2) tubercles are conical on the inner whorls, but become

prominently elongated in the direction of the ribs in later whorls. The sub-

marginal (3) tubercles are conical to radially elongated, whilst the marginal (4)

and external (5) tubercles are clavate.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 165

GSO CT differs from SAS—H139 in having the lateral tubercle situated

virtually at midflank, compared to the dorsal third in the latter.

The keel is low and entire.

Discussion

Collignon (1948) correctly interpreted T. texanus s.s. and removed all

European references to this species from the strict synonymy. Apart from the

typical form, he recognized two distinct varieties, var. hispanica and var. gallica,

but later (1966a) elevated them to specific rank. Young (1963) added another,

T. texanus twiningi, as a subspecies. Differences between the four subspecies

or varieties are based mainly on density of ribbing and details of ornamentation.

T. texanus texanus appears to have single ribs only, numbering about 20 to 21

per whorl. T. texanus twiningi has four to six more ribs per whorl than the

nominate subspecies. T. texanus gallica has a sub-ovoid whorl section, and

denser costation than the nominate subspecies, and the lateral tubercle is

situated on the dorsal third of the flanks. 7. texanus hispanica also has denser

costation, but ribbing starts at the umbilical wall and the lateral tubercle

migrates ventrally until it is finally situated at midflank.

T. texanus s.1. is not a very common species, hence it is difficult to decide

whether the four varieties, subspecies or species really merit separation, or

whether this is merely another example of morphological classification in the

texanitids. If large collections were available, as in the case of P. stangeri or

T. soutoni, these differences could possibly all be incorporated in the intra-

specific variation of a single species. Young (1963: 82) separated T. texanus

twiningi from the nominate subspecies purely on the grounds of stratigraphic

separation, stating that ‘if the two forms, T. texanus texanus and T. texanus

twiningi occurred together, there would be no need for the new name’. There

does, however, seem to be an age difference between the two subspecies, each

being utilized to designate a biozone (Young 1963: 22, text-fig. 33).

Of the South African specimens, SAS—H139 is best referred to T. texanus

gallica, having the lateral tubercle situated at the dorsal third of the flanks.

The Pondoland specimen GSO CT has the lateral tubercle situated at

midflank on the body chamber, and may be referred to T. texanus hispanica.

It should be pointed out, however, that it lacks the extension of ribbing on to the

umbilical wall, alleged to be characteristic of T. texanus hispanica.

Occurrence

Texanites texanus texanus appears to be restricted to Texas, although

Peron (1897: 49-50) has also recorded the species from Mansourah in Algeria.

Without figures the latter record is questionable. T. texanus twiningi is also

restricted to Texas. T. texanus gallica has been recorded from France, Bulgaria,

Italy, South America, Texas and Madagascar. T. texanus hispanica is known

from Spain and Madagascar.

166 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 125. Texanites texanus (Roemer, 1852). A. SAS-H139. x 1. B. Unnumbered specimen

in Cape Town branch of Geological Survey.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 167

Texanites umzambiense sp. nov.

Figs 126-129, 152A

Holotype

SAM-PCP5714 (Figs 126-129), Bed C6 south of locality 1, on the southern

side of the Umzamba River Estuary, Pondoland, Transkei, Umzamba Forma-

tion, Middle Santonian.

Etymology

Named after the Umzamba River, Pondoland, Transkei.

Fig. 126. Texanites umzambiense sp. nov. Holotype SAM-—PCP5714. x 0,59.

168 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

221,0 59,0(26,7) 66,0(29,7) 0,89 99,0(44,8) 28 28

Description

Early whorls up to 26 mm

The protoconch is absent, and the initial smooth stage appears to be

extremely short or absent (Figs 129, 152A). Ornament consists of strong

ventrolateral spines which lean against and into the umbilical wall of the

succeeding whorl. On the innermost whorl preserved, these spines are impressed

into the umbilical wall to such an extent that the whorl appears angular when

viewed laterally. The spines arise from low, broad swellings which cover the

whole flank. Spine density on the innermost two whorls is 6 and 11 per whorl

respectively.

Beyond a diameter of 11 mm the whorl section becomes more angular,

with a near vertical umbilical wall and weakly inflated flanks. The broad bases

of the ventrolateral spines now begin forming distinct single ribs which cover

the flanks of the whorls. Distinct, radially elongated umbilical tubercles start

appearing at the umbilical edge. The base of each of these is elongated obliquely

forward over the umbilical wall. Rib density at this stage is 21 per whorl, the

interspaces being as wide as the ribs. The ventrolateral spines progressively

become less prominent, and eventually appear as spirally elongated clavi in the

umbilical seam.

26 mm and beyond

At a diameter of about 26 mm faint lateral (2) tubercles start appearing

at about midflank. Simultaneously the ventrolateral clavi start migrating away

from the umbilical suture to reveal the 4th row of spirally elongated tubercles.

With increasing diameter the umbilical tubercles become increasingly clavate,

pointing obliquely inward. The lateral tubercles eventually migrate towards

the ventral third of the flanks, and the third row to the dorsal third, whilst the

4th row remains in the umbilical seam. Rib density at diameters of 62 and

135 mm is 27 and 24 per whorl respectively. On the outer phragmocone whorl

complete ornament is visible (Fig. 126). The marginal (4) and external (5)

tubercles are situated close together at the ventrolateral edge, and both are

prominently clavate. The ventral keel is undulating, being highest in the inter-

tubercular area. The preserved body chamber consists of half a whorl. There is

no distinct change in ornament at the beginning of the body chamber. On the

greater part of the late body chamber, ornament becomes weakened and

irregular due to damage to the shell.

Discussion

Despite being monotypic, this species is easily distinguished from the

predominantly younger species belonging to the groups of Texanites soutoni

CRETACEOUS FAUNAS FROM SOUTH AFRICA 169

Fig. 127. Texanites umzambiense sp. nov. Holotype SAM-PCP5714, x 0,74

170 ANNALS OF THE SOUTH AFRICAN MUSEUM

and Submortoniceras woodsi (described below). None of these specimens has the

marginal and external tubercles situated as close together as the present species,

or possesses an undulating keel.

The closest ally to, and probably direct ancestor of, this species seems to

be Plesiotexanites collignoniforme sp. nov. described above (p. 89). Both

species have the marginal and external tubercles approximated, and an

undulating keel. 7. umzambiense is here separated from P. collignoniforme

mainly because of the earlier appearance of the lateral tubercle (26 mm v.

Fig. 128. Texanites umzambiense sp. nov. Holotype SAM-PCP5714. A. x 1.

B. Scale bar in millimetres.

171

CRETACEOUS FAUNAS FROM SOUTH AFRICA

in millimetres.

Holotype SAM-PCP5714. Drawing to illustrate

Scale

early ontogeny

Fig. 129. Texanites umzambiense sp. nov.

172 ANNALS OF THE SOUTH AFRICAN MUSEUM

50 mm), and a more inflated whorl section on the phragmocone. Quite obviously

the ontogenetic character of differentiation between Texanites and Plesio-

texanites becomes evident here.

As noted above (p. 98), this could point to the beginning of the geographic

separation of the Zululand and Pondoland texanite faunas.

T. texanus hispanica, also reported from the Umzamba Formation above

(p. 162), bears superficial similarity in general form, but does not have the

external and marginal tubercles as closely spaced and lacks an undulating keel.

T. collignoni is related in having an undulating keel, but generally has a

much more compressed whorl section and different arrangement of tubercles.

T. mikobokensis from the Upper Santonian of Madagascar is another

similarly evolute species, but has a much more compressed whorl section and

different spacing of lateral ornament (see Collignon 1966a, pl. 509 (fig. 2019)).

Occurrence

Middle Santonian of Pondoland, Transkei.

Group of Texanites soutoni (Baily, 1855)—Submortoniceras woodsi (Spath, 1921)

Texanitids of the group centred on the plexus of 7. soutoni and S. woodsi

form the bulk of the texanitids in the present collection, and merit special

attention, not only because of numerical superiority and stratigraphic import-

ance, but because they illustrate

(i) what appears to be a partial geographic isolation of two contemporaneous

groups within a species with some intermingling,

(ii) a striking evolutionary sequence in both populations, spanning the period

from Middle Santonian to Early Campanian, starting with a normal

evolute Texanites, and ending with an involute Submortoniceras, with no

clearcut break, and

(iii) a tremendous intraspecific variation, especially as far as ornamentation

and suture lines are concerned which causes one to have serious doubts

about the validity of current texanitid systematics.

The texanitids occur mainly in two areas—the type section of the Umzamba

Formation at the Umzamba Estuary, Transkei, locality 1 of the authors

(Kennedy & Klinger 1975: 281; Klinger & Kennedy in press) and the south-

eastern shores of False Bay, Zululand, at locality 105 (Kennedy & Klinger 1975:

296; herein Fig. 130) continuing the section in the cliffs at locality 74 (Kennedy

& Klinger 1975: 283, fig. 8). Minor occurrences connecting the two main areas

are at locality 14 (Kennedy & Klinger 1975: 283) near Umkwelane Hill, sub-

surface deposits near Richards Bay at locality 6 (Kennedy & Klinger 1975: 282),

and similar deposits at Durban at locality 5 (Kennedy & Klinger 1973; 1975:

282). Current evidence seems to suggest that the deposits at False Bay, Zulu-

land, represent a deeper water facies than the shallower water transgressive

facies of the Umzamba Formation.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 173

— = a

G Silts with aragonitic concretions

Pseudoschloenbachia? sp.

'Heteroceras' amapondense, Hyphantoceras

sp. Submortoniceras condamyi

Submortoniceras condamyi, Hyphantoceras

sp., inoceramids, large indeterminate

texanitid

Submortoniceras condamyi, INoceramus

sp., aragonitic concretions

Texanites soutoni natalense, Kossmati-

ceras sp., Scaphites sp., inoceramids

i vas SS Texanites presoutoni natalense, Pseudo-

D> cf phyllites latus, phyllites latus, Inoceramus sp.

Fig. 130. Stratigraphic section at locality 105 on the south-eastern shores at False Bay.

174 ANNALS OF THE SOUTH AFRICAN MUSEUM

The material is extremely variable, but data gained from detailed zonal

collecting by the authors, examination of material collected zonally by Gevers,

and indications of relative stratigraphic position of specimens in older collec-

tions—such as encrustation by modern epizoans indicative of a low strati-

graphic position at the type section of the Umzamba Formation—permit

partial interpretation of the species centred on the T. soutoni—S. woodsi plexus,

both in terms of spatial and temporal variation.

At first glance, the texanitine faunas of Pondoland and False Bay appear

to be completely different. This apparent ‘difference’ is greatly enhanced by the

dissimilar lithologies and associated faunas (the latter to be discussed fully in

Klinger & Kennedy in press). Specimens from False Bay generally retain

calcareous white shell material in a buff-weathering sandy silt, whereas the

Pondoland specimens are mainly preserved in crystalline calcite in a dark

greyish-green glauconitic silt. In addition, there is a distinct difference in size

between the texanitines of both areas; those from Pondoland are generally

gigantic when compared with the normal-sized specimens from False Bay.

Detailed stratigraphic collecting shows that there is a distinct trend in

both faunas towards acquisition of submortoniceratine shell-form (Figs. 131-

132). True texanitids with umbilical diameters of the order of c. 45 per cent

occur near the bases of both sections, and through gradually decreasing umbilical

width and whorl breadth, give way to true submortoniceratids towards the

higher levels in the sections.

Apart from differences in size, real differences are to be found in the mode

of acquisition of Submortoniceras ornament, and in the relative width of the

lobes of the suture lines. In Pondoland, the submortoniceratine characters are

developed in the ‘traditional’ way, i.e. through gradual weakening of ornament

from the inside outwards. At False Bay, however, a great proportion of speci-

mens has inner whorls with ornament weaker than that of the outer whorls

and retains tuberculation on part of the body chamber. It may thus be said that

submortoniceratine characteristics are acquired caenogenetically in Pondoland,

but proterogenetically at False Bay. As far as suture line is concerned, the

False Bay specimens generally have much wider and shallower lobes exposed on

the flanks than their Pondoland counterparts.

Detailed examination of the associated fauna, however, has shown that the

stratigraphic interval exposed at the type section of the Umzamba Formation up

to Bed A7-8 (Klinger & Kennedy in press) corresponds approximately to that ex-

posed at locality 105 and the higher parts of the section at locality 74 (Kennedy &

Klinger 1975: 293, fig. 8). Furthermore, typical, though sometimes dwarfed or

smaller, Pondoland faunas occur in the Richards Bay and Umkwelane Hill areas,

and even at False Bay, while typical False Bay faunas occur at Umkwelane Hill,

indicating an area of intermingling between apparently isolated faunas.

The authors are now able to correlate the texanitine faunas of Pondoland

and Zululand, and it is now possible to produce a series of specimens of more

or less equal involution and age, ranging from completely smooth to coarsely

CRETACEOUS FAUNAS FROM SOUTH AFRICA 175

Holotype

Jexanites soutoni soutoni

Dead-end ?

‘var. inflata

var. cOmpressa Texanites soutoni soutoni

Texanites presoutoni presoutoni

MIDDLE SANTONIAN — — — — — — UPPER SANTONIAN — — — — — — — —LOWER CAMPANIAN

Texanites umzambiense

‘(eee VARIATION =

Fig. 131. Diagrammatic illustration showing suggested lines of evolution and intraspecific

variation in species of the Texanites soutoni-Submortoniceras woodsi plexus at the type section

of the Umzamba Formation.

LOWER CAMPANIAN

UPPER SANTONIAN —

176 ANNALS OF THE SOUTH AFRICAN MUSEUM

woods! natalense

forma typica

var. inflata Texanites soutoni natalense var. COmpressa

Texanites presouton! natalense

Fig. 132. Diagrammatic illustration showing suggested lines of evolution and intraspecific

variation in species of the Texanites soutoni-Submortoniceras woodsi plexus in the False Bay

region of Zululand.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 177

ornamented on the inner whorls, all occurring at the same stratigraphic level.

The extreme variation at the same stratigraphic level, combined with: the

lack of abrupt vertical changes in the population, makes it difficult to differ-

entiate satisfactorily between the various groups. As there are no visible abrupt

changes in the population, differentiation will have to be arbitrary, and here

umbilical width seems to be the most feasible choice. The Pondoland and Zulu-

land faunas, where sufficiently different, are separated at subspecific level. On

the latter basis, the following morphological taxa may be recognized:

U =c. 45% with external and marginal tubercles separated and ribbing pre-

dominantly single, especially on the body chamber = 7. presoutoni sp.

nov.

T. presoutoni presoutoni ssp. nov. Holotype is SAM-—PCP5712 from the

Umzamba Formation, Umzamba Cliff at locality 1, presumably Bed Al.

T. presoutoni natalense ssp. nov. Holotype is SAS-—H126A/12 from the

St Lucia Formation, locality 105, Bed A.

U=c. 40% =T. soutoni s.1.

T. soutoni soutoni (Baily, 1855). Holotype is the specimen figured by

Baily (1855, pl. 11, fig. la—c), here refigured as Figure 143.

T. soutoni natalense ssp. nov. Holotype is SAS—H126B/3 from the St Lucia

Formation, locality 105, Bed B.

In both the above subspecies an inflated and compressed variety may be

recognized, both apparently with a tendency towards acquisition of submortoni-

ceratine characters, but it appears the compressed variety is a dead-end. (See

Figs 131-132.)

U =c. 35% = Submortoniceras woodsi s.\.

S. woodsi woodsi (Spath, 1921). Holotype is SAM-—5451 from Umkwelane

Hill, Zululand, the specimen figured by Spath (1921, pl. 21 (fig. la-d)),

here refigured as Figure 186.

S. woodsi natalense ssp. nov. Holotype is SAS—Z1875 from the St Lucia

Formation, locality 105.

U =c. 30% = S. condamyi.

S. condamyi condamyi Collignon. Lectotype herein designated is the speci-

men figured by Collignon (1948, pl. 18(12) (fig. 2-2b)) from the Lower

Campanian of Berere, Madagascar.

S. condamyi umzambiense ssp. nov. Holotype is SAM-—PCP5717 from the

Umzamba Formation, Umzamba Cliff, locality 1, Bed A7.

This framework (see also Figs 131-132) should be seen as a working basis

towards classifying the species centred on 7. soutoni-S. woodsi, and not as a

rigid, compartmentalized framework. Many of the specimens discussed below

could be referred to more than one species or subspecies. This is in part due to

the extreme horizontal variation and also the continuous vertical transition

from one species to another. In addition, this classification is hampered by the

fact that it has to accommodate the holotypes of established species which in

178 ANNALS OF THE SOUTH AFRICAN MUSEUM

themselves are already transitional between species (or even genera), e.g. T.

soutoni or incomplete, e.g. S. woodsi. Material described by Young (1963) from

the Gulf Coast of America also falls within the range of variation of this species

group, and has to be accommodated.

Texanites presoutoni presoutoni ssp. nov.

Figs 133-137, 152C

Mortoniceras soutoni (Baily): Woods, 1906: 337, pl. 43 (fig. 1). ?Van Hoepen 1921: 38 pars,

pl. 11 only.

Holotype

SAM-PCP5712 (Figs 133-135), locality 1, basal beds at Umzamba Cliff,

Pondoland, Transkei, Umzamba Formation, Upper Santonian.

Material

SAM-4828, locality 1, basal beds at Umzamba Cliff, Pondoland, Transkei;

and BMNH-C19447 from an unknown horizon at the same locality, Umzamba

Formation, Upper Santonian.

Dimensions

D Wh Wb Wb: Wh U Int. Ext.

PCP5712 387,0 — 122,0(31,5) — 181,0(46,8) 30 30

SAM4828 230,0 -- 81,0(35,2) —_— 97,0(42,0) 2 Daf

Description

The material, though limited in numbers, is very varied. Coiling is loose,

with an umbilical diameter of 42 to 47 per cent. The whorl section may

be quadrate in the very early stages, but later becomes compressed, higher than

wide throughout.

SAM-—PCP5712 (Figs 133-135, 152C) has the innermost whorls preserved,

illustrating the ontogenetic development. After the initial smooth stage, long

spinose ventrolateral tubercles appear, leaning against the umbilical wall.

Smaller umbilical (1) tubercles appear next, followed by lateral (2) tubercles at

a diameter of c. 20 mm.

Ornament remains basically the same throughout the rest of the phragmo-

cone, though differing considerably in terms of strength and spacing. SAM-

PCP5712 (Fig. 133) thus has much coarser ornament on the phragmocone than

SAM-4828 (Fig. 136). BMNH-C19447 (Fig. 137) has as sparse costation as

SAM-PCP5712 (Fig. 133), but by no means as strongly developed tuberculation.

All the specimens have single ribbing throughout—a feature here considered

as being ‘primitive’.

Towards the body chamber the lateral (2) and submarginal (3) tubercles

become effaced, and on the later part all ornament weakens.

The suture varies, but has stout saddles E/L and L/U, and long, thin

lobes L and U,.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 179

Fig. 133. Texanites presoutoni presoutoni sp. nov. Holotype SAM-—PCP5712. x 0,35.

ANNALS OF THE SOUTH AFRICAN MUSEUM

180

horls to illustrate ontogeny.

Inner W.

ites presoutoni presoutoni sp. nov. Holotype SAM-—PCP5712. Close-up of

Texan

. 134.

Fig

CRETACEOUS FAUNAS FROM SOUTH AFRICA 181

Fig. 135. Texanites presoutoni presoutoni sp. nov. Drawing of inner whorls based on holotype.

Discussion

The status of this species is admittedly somewhat artificial, but forms a

convenient starting point for describing the species of the T. soutoni-S. woodsi

plexus.

The specimen figured by Van Hoepen as Mortoniceras soutoni (1921, pl. 11)

has ornament on the inner whorls closely resembling that of the holotype of

the species, but denser, fiexuous ribbing on the body chamber and an umbilical

width of c. 43 per cent. It should probably also be referred to the present species,

but the authors have not been able to trace it in the Transvaal Museum for

182 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 136. Texanites presoutoni presoutoni sp. nov. Paratype SAM-4828. x 0,6 The specimen

figured by Woods (1906, pl. 43 (fig. 1)).

definite identification. Haas (1942: 17) had already suggested that Van Hoepen’s

figured specimen be separated from TJ. soutoni as variety densicosta. Apart

from the fact that this cannot be accepted as a valid designation, the term

densicosta, should it be accepted in formal nomenclature, is extremely mis-

leading, as in this case it applies only to the body chamber ornament. The

authors’ comments on this specimen (Klinger & Kennedy 1977: 97) are still

partially valid, but in suspecting different ontogenetic development the authors

CRETACEOUS FAUNAS FROM SOUTH AFRICA

gasses

Fig. 137. Texanites presoutoni presoutoni sp. nov. Paratype BMNH-C19447.

PE:

183

184 ANNALS OF THE SOUTH AFRICAN MUSEUM

were misled by differences in preservation and the extreme intraspecific variation

in 7. soutoni.

Both Haas (1942: 12) and Young (1963: 85) regarded Woods’s figured

specimen (SAM-4828) of Mortoniceras soutoni as not being conspecific with

the holotype, but gave no reasons for this. The wide umbilicus, single ribbing

throughout and long, narrow lobes in the suture of this specimen are all charac-

teristic of the present subspecies.

T. presoutoni presoutoni is closely connected to T. soutoni soutoni by speci-

mens such as SAM-—PCP5713 and SAM-—PCP5718 (Figs 144-145) with only a

few bifurcations and a slightly narrower umbilicus.

T. presoutoni s.s. differs from its subspecies in the False Bay region of

Zululand, T. presoutoni natalense, mainly in losing tuberculation on the body

chamber, whereas the latter remains tuberculate. The Pondoland subspecies

attains larger dimensions. *

Occurrence

Lower part of Upper Santonian of Pondoland, Transkei.

Texanites presoutoni natalense ssp. nov.

Figs 138, 139B, 140-142

Holotype

SAS-H126A/12 (Figs 138, 139B), Bed A locality 105, south-eastern shores

of False Bay, Zululand, St Lucia Formation, Upper Santonian.

Material

Paratypes are SAS-Z1140 and SAM-—PCZ5885, both from the same locality

as the holotype.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

H126A/12 301,0 — 106,0(35,2) — 130,0(43,2) 17 x2

Z1140 226,0 62,0(27,4) 76,0(33,6) 0,81 101,0(44,7) 31 31

PCZ5885 177,0 51,0(28,8) 62,0(35,1) 0,82 75,0(42,4) 28 2H

Description

Coiling is evolute, with an umbilical width of 42 to 44 per cent of the

total diameter. The whorl section is massive, higher than wide throughout with

a near vertical umbilical wall, and, in intercostal section, little-inflated flanks

converging to a broadly rounded venter. Maximum whorl breadth is near the

dorsal third of the flanks in intercostal section, and in costal section at the site

of the lateral tubercle, which is very prominent.

Ornament on the phragmocone consists of radially elongated umbilical

tubercles (1), arising at the umbilical edge, and progressively clavate lateral,

submarginal, marginal and external (2—5) tubercles. At larger diameters on the

CRETACEOUS FAUNAS FROM SOUTH AFRICA 185

Fig. 138. Texanites presoutoni natalense ssp. nov. Holotype SAS-H126A/12. x 0,53.

UMS th

B. Texanites

. 00

~wn

nel

4 Q

aye

NAN a

Sy ES)

fe)

Me)

Hm -

S38

fon

5 en |

CRETACEOUS FAUNAS FROM SOUTH AFRICA 187

Fig. 140. Texanites presoutoni natalense ssp. nov. Paratype SAS-Z1140. x 0,6.

phragmocone the lateral (2) tubercles may become conical to radially elongated,

as the umbilical ones. Bifurcations are not very common on the late part of the

phragmocone. On the body chamber ribbing becomes narrower, but lateral and

submarginal (2 and 3) tuberculation does not become effaced.

The suture consists of blocky saddles and narrow lobes, but proportions

vary considerably in three available specimens. The lateral lobe (L) is long,

narrow and trifid, with a bifid median prong in the holotype (Fig. 142), but

wider and shorter in paratype SAM-PCZ 5885 (Fig. 141).

188 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 141. Texanites presoutoni natalense ssp. nov. Paratype SAM—PCZ5885. x 0,6.

Discussion

Of the three available specimens, only the holotype has the body chamber

preserved, which shows the presence of the full complement of ornament thus

distinguishing it from its Pondoland counterpart, 7. presoutoni presoutoni.

Apart from this, the general mode of ornament on the phragmocone, shell

shape and suture line are compatible. The two paratypes, with occasional

bifurcations, are already transitional to T. soutoni natalense ssp. nov. (described

below), and may be compared with Pondoland specimens such as SAM-—

PCP5718 (Fig. 144) which are transitional between 7. presoutoni s.s. and T.

SOUtONI SS.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 189

Cad

eel See te -"¢

7 C4 ow @ eq |

f} ‘ e i \

ns 5 sey, ehMhee--—”

> =Z— = wae SF 8

Fig. 142. Texanites presoutoni natalense ssp. nov. Holotype SAS—-H126A/12. Suture line.

Scale bar in millimetres.

Occurrence

Upper Santonian of Zululand.

Texanites soutoni soutoni (Baily, 1855)

Figs 143-151, 152B, 153-163

Ammonites soutoni Baily, 1855: 455, pl. 11 (fig. 1a-c).

Mortoniceras soutoni (Baily): Spath, 1921: 234, pl. 20 (fig. 4); 1922: 136, pl. 7 (fig. 4). Van

Hoepen, 1921: 38, pl. 10 (zon pl. 11 =T. presoutoni s.s. sp. nov.).

Non Mortoniceras soutoni (Baily): Woods, 1906, 337, pl. 43 (fig. la—b) (=T. presoutoni s.s. sp.

nov.).

Texanites soutoni (Baily): Matsumoto, 1955: 42, text-fig. 3. Collignon, 1966: 70, pl. 483

(fig. 1956). Klinger & Kennedy, 1977: 89, fig. 9.

Non Mortoniceras sp. aff. soutoni Spath, 1922: 235 (=T. soutoni natalense ssp. nov.).

? Mortoniceras aff. soutoni Spath, 1925: 199.

? Texanites cf. soutoni Collignon, 1948: 78, pl. 9(3) (fig. 1a—b).

Non Texanites soutoni (Baily): Kennedy & Klinger, 1972: pls 72-73 (with Spinaptychus)

(=T. soutoni natalense ssp. nov.).

Type

Holotype is BMNH-C47261, the specimen figured by Baily (1855, pl. 11

(fig. 1)), here refigured as Figure 143, locality 1, Umzamba Cliff, Pondoland,

Transkei, Umzamba Formation, Upper Santonian.

Material

SAM-—PCP5713-5715, PCP5718, SAM-13090, SAM-7076—-7077, SAS-

P747, P1334, P1398, NMB-D1605a-b, BMNH-C19442, C19454, C19461,

C47261, all from locality 1, Umzamba Cliff, Pondoland, Transkei, Umzamba

Formation, Middle to Upper Santonian; SAS-—Z306 and SAM-PCZ5885,

190 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 143. Texanites soutoni soutoni (Baily, 1855). Photograph of cast of holotype, BMNH-—

C47261. x 0,34. Note that Baily’s figure is a mirror image.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 191

locality 14, near Mfolozi, St Lucia Formation, Santonian II-III to Campanian J;

SAM-PCZ5884, locality 6, excavations near Richards Bay, St Lucia Formation,

Santonian II-III to Campanian I; SAM-—PCZ 5903, locality 74, Die Rooiwalle,

Zululand, St Lucia Formation, Santonian to Campanian; and possibly SAM-FB

from an unknown locality in False Bay, probably also locality 74.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

PCP5714 231,0 66,0(28,6) 74,0(32,0) 0,89 107,0(46,3) 30 30

PCP5713 200,0 56,0(28,0) 70,0(35,0) 0,80 82,0(41,0) 28 28

SAM-7077 337,0 — 106,0(31,5) — 149,0(44,2) 38 38

P747 357,0 78,0(21,8) 131,0(36,7) 0,59 145,0(40,6) 36 36

P1334 329,0 89,0(27,1) 110,0(33,4) 0,81 140,0(42,6) DIL SRD)

D1605b 259,0 — 93,0(35,9) — 105,0(40,5) 30 30

PCP5718 356,0 — 127,0(35,7) — 151,0(42,4) 30 32

Z306 237,0 66,0(27,8) 93,0(39,2) 0,71 91,0(38,4) 26 30

C47261 444,5 114,3(25,7) 152,4(34,3) 0,75 177,8(40,0) 35 37

Diagnosis

Texanitid with umbilical width of approximately 40 per cent of total

diameter, whorl section higher than wide throughout; with venter narrower

than dorsum. Ornament on innermost whorls variable, ranging from virtually

smooth to strong, with variable number of bifurcations. Towards the body

chamber lateral ornament becomes attenuated. Generally one or two bifurca-

tions on outer body chamber whorl. Suture variable.

Description

As here interpreted, the species is very variable, consequently ample

illustrations are provided in lieu of lengthy descriptions.

Two varieties within the species may be recognized, both occurring together

near the base of the section exposed at Umzamba Cliff: an inflated broad-

whorled variety, e.g. SAM-PCP5718 (Figs 144-145), and a more evolute,

slender-whorled and compressed variety, e.g. SAM-7077 (Fig. 146), which

may here be labelled var. inflata and var. compressa for descriptive purposes.

Both extremes, however, are connected by specimens such as SAS—P747 (Figs

147-148) and SAS-P1334 (Fig. 149). Specimens SAM-7077 (Fig. 146), SAS—

P747 (Fig. 147) and SAS—-P1334 (Fig. 149) illustrate the variation in strength

of ornament in the species. Details of these differences in the ontogeny are

discussed below. Stratigraphic data seem to suggest that the holotype of T.

soutoni s.s. may be derived from variety inflata through reduction of the umbilical

diameter, probably via specimens such as SAM-—PCP5715 (Fig. 150). Variety

compressa possibly also evolved in the direction of Submortoniceras via a

specimen such as SAM-—7076 (Fig. 151) with attenuated ornament on the outer

whorls but a relatively wide umbilicus. This latter trend appears to have been

a dead-end (Fig. 131), whereas forms such as the holotype of JT. soutoni s.s.

gradually evolved into Submortoniceras woodsi.

192 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 144. Texanites soutoni soutoni (Baily, 1855). SAM-—PCP5718. Variety here referred to

informally as var. inflata. x 0,41.

Preservation of material at the Umzamba Estuary is generally much better

than that of temporally equivalent strata in Zululand, and a number of speci-

mens have the inner whorls preserved, permitting a full description of the

ontogeny of the species. None of the specimens, however, has the protoconch

preserved.

Details of the ontogeny are illustrated in Figures. 152-153. Even on the

CRETACEOUS FAUNAS FROM SOUTH AFRICA 193

Fig. 145. Texanites soutoni soutoni (Baily, 1855). SAM-—

PCP5718. Variety here referred to informally as var. inflata.

x 0,48.

194 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 146. Texanites soutoni soutoni (Baily, 1855). SAM-—7077. Variety here referred to

informally as var. compressa. X 0,41.

innermost whorls differences in strength of ornament are obvious when com-

paring SAM-—PCP5713 (Fig. 152B) with SAS—P747 (Fig. 153C). The initial

smooth stage is short, except in SAS—P747, where it persists to a diameter of

about 10 mm. The ventrolateral tubercles develop first, and in most cases occur

as long, curved spines with broad bases leaning against the umbilical wall.

In this respect SAS—P747 (Fig. 153C) seems to differ from the rest of the

specimens in appearing to lack the strong development of ventrolateral spines.

Close investigation of the inner whorls of SAS—P747 (Fig. 153C), however,

CRETACEOUS FAUNAS FROM SOUTH AFRICA 195

Fig. 147. Texanites soutoni soutoni (Baily, 1855). SAS-—P747. Specimen connecting between

varieties compressa and inflata in having a very compressed whorl section, but not as evolute

coiling. x 0,42.

196 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 148. Texanites soutoni soutoni (Baily, 1855). SAS—P747. Specimen connecting between

varieties inflata and compressa in having extremely compressed whorls, but relatively narrow

umbilicus. x 0,5.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 197

Fig. 149. Texanites soutoni soutoni (Baily, 1855). SAS—P1334. Specimen connecting between

varieties inflata and compressa, and with very weak lateral ornament. x 0,55.

198 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 150. Texanites soutoni soutoni (Baily, 1855). SAM-—PCP5715. x 0,41.

reveals the vestiges of two tubercles and corresponding indentations on the

umbilical wall of the succeeding whorl, indicating that spines could have been

present and that their absence could be partially due to the state of preservation.

Small, rounded umbilical tubercles occur next, followed by a row of lateral

tubercles. With increasing diameter the ventrolateral spines in the umbilical

suture become smaller and more clavate, and migrate away from the umbilical

wall to expose a fourth row of tubercles on the flanks. Thereafter ornament

remains basically the same, although details differ, as shown in the Figures.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 199

Fig. 151. Texanites soutoni soutoni (Baily, 1855). SAM-7076. Specimen with attenuated

ornament, trending towards Submortoniceras, but apparently a dead-end lineage. x 0,42.

(See also Fig. 131.)

The suture is very variable as Van Hoepen (1921) had already noted. Apart

from differences in the length and width of the second lateral saddle (L/U,)

already discussed and figured by Van Hoepen (1921), the most obvious and

easiest recognizable differences are to be found in the length and incision of the

saddles and lobes exposed on the flanks. Data here are scant, but it appears as

if there is a tendency towards greater complexity of the suture line higher up

in the stratigraphic sequence (Fig. 161) leading towards the formation of the

ANNALS OF THE SOUTH AFRICAN MUSEUM

200

Yj 7

Vial

to illustrate

Holotype SAM-—

Texanites pre-

imens

Holotype SAM-PCP5712

- NOV.

whorls of spec

inner

toni SAM—PCP5713

ites umzambiense sp

ton

hotographs of

A. Texan

i presou

ir p

Texanites soutoni sou

souton

Stereopa

152

ontogenetic development

Fig

PCP5714

201

CRETACEOUS FAUNAS FROM SOUTH AFRICA

ites

SAM-7077

imens of Texan

ion.

ic variat

SAS-P747

inner whorls of spec

—P1398

. SAS

illustrate the ontogenet

hotographs of

ir p

ton

Fig. 153. Stereopa

soutoni sou

202 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 154. Texanites soutoni soutoni (Baily, 1855). SAS—-Z306. A dwarfed specimen from the

environs of Umkwelane Hill. x 0,56.

narrow-stemmed, deeply incised saddles and lobes of Submortoniceras woodsi

and S. condamyi. The lateral lobe (L) appears to become shorter and wider

with splayed ends, and to change from subtrifid to more symmetrically bifid.

Comparison of the sutures of T. presoutoni s.s. (specimens SAM—PCP5712 and

SAM-4828, both from the lower parts of the sequence at Umzamba), through

normal representatives of T. soutoni s.s. (SAS-PCP5718, SAS—P747 and NMB-

D1605B) and the holotype of T. soutoni s.s. (C47261 and a related form,

SAM-—PCP5715) through to Submortoniceras woodsi woodsi and S. condamyi

CRETACEOUS FAUNAS FROM SOUTH AFRICA 203

Fig. 155. Texanites soutoni soutoni (Baily, 1855). SAS—Z306. A dwarfed specimen from the

environs of Umkwelane Hill. x 0,66.

204 ANNALS OF THE SOUTH AFRICAN MUSEUM

umzambiense seems to illustrate the point (Fig. 161).

As far as can be ascertained, there seems to be no direct relationship

between complexity of suture line and ornament.

Discussion

Despite being one of the first ammonites to be described from the Cre-

taceous deposits at the Umzamba Estuary, this species has been consistently

misinterpreted. Both Spath (1922: 136) and Van Hoepen (1921: 38-45) com-

mented on the extreme variation of T. soutoni in their collections. Whereas

Fig. 156. ? Texanites soutoni soutoni (Baily, 1855). SAM-PCZ5903, from

Die Rooiwalle, Zululand. x 0,68.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 205

Spath concentrated mainly on density and character of ribbing (presence or

absence of bifurcations) and to a lesser extent on the tightness of coiling, Van

Hoepen paid close attention to the configuration of the suture lines and came

to the conclusion that, in some cases at least, the comparative significance of

the suture line at more or less the same age is fiction. Apart from these two

authors, little substantial research has been done on this species.

The largest known collections of T. soutoni are housed in the collections

of the British Museum (Natural History), the South African Museum, Geo-

logical Survey of South Africa (Pretoria), and the Transvaal Museum. Exami-

nation of these collections, virtually all from the Umzamba Estuary, shows that

hardly two specimens are alike. The sediments at Umzamba represent a con-

densed sequence (Klinger & Kennedy 1977: 105, and in press). Stratigraphic

data are thus essential for meaningful systematics. Unfortunately very little

stratigraphic data are available in the literature. Baily (1855: 455) stated of the

holotype that Thomas Souton had ‘extracted it . . . from a very hard stratum

high up the cliff’. Griesbach (1871: 62 (table)) lists Ammonites soutoni as occur-

ring in his Bed d. Plows (1921: 63) recorded a specimen of Mortoniceras soutoni

in his Bed 14. Rogers & Schwarz (1902: 41) and Gevers (in Rennie 1930: 253)

record Mortoniceras soutoni from the basement beds at Umzamba.

Detailed collecting by the authors at the type section of the Umzamba

Formation, examination of the material collected zonally by Gevers, and indi-

cations of relative stratigraphic position of specimens in older collections, such

as encrustation by modern epizoans, indicative of a low horizon at the type

section which is inundated by the present sea during high tide, permitted partial

explanation of the species plexus centred on T. soutoni as outlined above

(Fig. 131). The ‘high horizon’ ascribed to the holotype of T. soutoni by Baily

tallies well with the present interpretation that’ submortoniceratine charac-

teristics are acquired gradually through decreasing umbilical width and pro-

gressive loss of ornament in earlier stages when passing higher up through the

sequence exposed at the Umzamba Estuary.

The question of whether Baily’s Ammonites soutoni should be referred to

Submortoniceras, as advocated by Spath (1953: 52) and Young (1963: 91), or

Texanites, following Matsumoto (1955: 42, 1970: 279) or Collignon (1948: 42,

1966a: 70), thus becomes academic, depending on where the boundary between

Texanites and Submortoniceras is drawn. According to the present classification,

the holotype of Ammonites soutoni is referred to the genus Texanites.

A complete, though dwarfed, specimen SAS—Z306 (Figs 154-155) from

locality 14 at Umkwelane Hill represents the first recording of this species from

Zululand.

SAM-PCZ5903 (Fig. 156) and SAM-FB (Fig. 157) are the only two

possible representatives of the nominate subspecies from the northern part of

Zululand at Die Rooiwalle, locality 74.

Specimen SAM-—5491 (Fig. 81) described by Spath (1921: 234) as Mortoni-

ceras aff. umkwelanense and considered related to T. soutoni, certainly does not

206 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 157. ? Texanites soutoni soutoni (Baily, 1855). SAM-—FB, a very large specimen, possibly

referable to the nominate subspecies from an unknown locality at False Bay, Zululand.

x 0,48.

207

CRETACEOUS FAUNAS FROM SOUTH AFRICA

from an unknown local

T1491

x 1

Mozambique.

Fig. 158. Texanites sp. aff. soutoni (Baily, 1855)

208 ANNALS OF THE SOUTH AFRICAN MUSEUM

belong to this species, but is an example of Plesiotexanites matsumotoi sp. nov.

described above.

The specimen described by Spath (1921: 235) as Mortoniceras aff. soutoni

from Umkwelane Hill, Zululand, belongs to the group of 7. soutoni s.1. but is

better referred to TJ. soutoni natalense ssp. nov. on account of the smooth inner

whorls.

Two very corroded specimens, TM1491 (Fig. 158) and TM1493 (Fig. 159),

described by Spath (1925: 199-200) as Mortoniceras aff. soutoni, are very

doubtful contenders. Apart from the fact that they were found in ‘Maputoland’

(Mozambique) and presented to the Transvaal Museum by a ‘Sefior Morreira’,

no other locality data are available. In view of their poor state of preservation

a definite identification is not possible. If they are, indeed, representatives of

T. soutoni, they extend the geographic range of the species from Pondoland

through Zululand and Mozambique to Madagascar.

Judging by similarities in ontogeny, 7. soutoni s.s. can be derived from

T. umzambiense sp. nov. or T. presoutoni s.s. sp. nov. (Figs 152-153). Unfortu-

nately stratigraphic data are insufficient for determining the exact phylogenetic

sequence, but it is assumed here that T. soutoni was probably derived from

T. umzambiense via T. presoutoni. Differences between T. soutoni s.s. and T. pre-

soutoni sp. nov. s.s. are gradational, being mainly a question of umbilical

width and frequency of bifurcations on the phragmocone as noted above

(p. 177). Specimens such as SAM—PCP5713 (Fig. 152B) or SAM-13090 (Fig.

160) with robust ornament consisting predominantly of single ribs on the

phragmocone, are to be considered transitional between the two species.

Similarly, the upper boundary between T. soutoni s.s. and Submortoniceras

woodsi is also gradational. Specimens with umbilical diameters in the vicinity

of 35 per cent and greatly attenuated ornament on the phragmocone are best

referred to Submortoniceras, rather than T. soutoni.

The Zululand counterpart of T. soutoni soutoni, T. soutoni natalense ssp.

nov., differs mainly in often having attenuated ornament on the inner whorls,

a generally stouter whorl section and wider and shallower lobes, but is just as

variable and grades laterally into the Pondoland subspecies.

In view of the extreme variation, comparisons with species outside southern

Africa become tenuous.

T. hourcgi Collignon from the Middle Santonian of Madagascar is similar

to the more evolute forms of T. soutoni s.s., but is more compressed. When

compared with T. soutoni s.s. doubt arises if the possession of regularly bifur-

cating ribbing in T. hourcqi is as important a characteristic as implied by Col-

lignon (1948: 79).

Young (1963: 90) erected a new species, T. Jonsdalei, on the basis of one

specimen and a questionable specimen, and included Collignon’s (1948: 78,

pl. 9(3) (fig. 1-la)) Texanites cf. soutoni in the synonomy of that species. As

interpreted here, Collignon’s specimen may easily be accommodated in the

variation of T. soutoni s.s., but not T. lonsdalei because of the much higher than

CRETACEOUS FAUNAS FROM SOUTH AFRICA 209

Fig. 159. Texanites sp. aff. soutoni (Baily, 1855). TM1439, from an unknown locality in

Mozambique. x 1.

210 ANNALS OF THE SOUTH AFRICAN MUSEUM

wide whorl section (see especially Young, pl. 51 (fig. 5)). Young (1963: 91),

however, paid more attention to similarities of ornament, and admitted that

the Texan specimen ‘may be crushed’. Even if the Texas specimen is crushed,

the umbilical width is predominantly of the order of 32 to 35 per cent, with only

one recording at 41,5 per cent. This places the species closer to Submortoniceras

woodsi, and Young (1963: 92) did, indeed, refer to this species (together with

Woods’s specimen of Mortoniceras soutoni (1906, pl. 43 (fig. 1)) and 7. roemeri

as being ‘close to the Submortoniceras—Texanites taxonomic boundary’ (Young

: eG,

—

Fig. 160. Texanites soutoni soutoni (Baily, 1855). SAM-—13090, a specimen transitional

between T. soutoni soutoni and T. presoutoni presoutoni sp. nov. X 0,65.

SUBMORTONICERAS

TEXANITES

CRETACEOUS FAUNAS FROM SOUTH AFRICA 211

T. soutoni holotype

T. soutoni

T. presoutoni

Fig. 161. Diagram illustrating apparent trend in suture line towards higher degree of

complexity in development from Texanites to Submortoniceras. Whorl section of

Texanites soutoni soutoni superimposed.

212 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 162. Texanites soutoni soutoni (Baily, 1855). BMNH-C19461.

(British Museum photograph.) x 0,95.

1963: 92). Until the question of the true whorl section of T. lonsdalei is resolved,

the species has to be maintained with some doubt, but bearing in mind the

affinity with the T. soutoni-S. woodsi plexus.

Detailed studies of the ontogeny of the species as outlined here (p. 194)

definitely allay Matsumoto’s suspicion (1970: 279) that T. soutoni could possibly

have Plesiotexanites inner whorls.

Occurrence

T’. soutoni s.s. is relatively common in the Upper Santonian of the Umzamba

CRETACEOUS FAUNAS FROM SOUTH AFRICA 213

Fig. 163. Texanites soutoni soutoni (Baily, 1855).

BMNH-C19461. (British Museum photograph.) x 0,95.

Formation of Pondoland at the type section, locality 1, and is also known from

borehole and other subsurface material near Richards Bay, Zululand (Klinger

& Kennedy 1977). Rare occurrences are known from Umkwelane Hill and the

False Bay area of Zululand. |

The species is very rare in Madagascar (Collignon 1948: 78), and as yet

no good specimens have been figured from that area. In view of the other close

similarities between Pondoland and Madagascar faunas, e.g. pseudo-

schloenbachiids, Hauericeras, etc., this is very surprising.

214 ANNALS OF THE SOUTH AFRICAN MUSEUM

Texanites soutoni (Baily) natalense ssp. nov.

Figs 164-185

Mortoniceras sp. aff. soutoni Spath, 1921: 235.

Texanites soutoni (Baily): Kennedy & Klinger, 1972: pls 72-73.

Etymology |

Refers to the geographic occurrence.

Holotype

SAS-H126B/3 (Figs 164-165), Bed B locality 105, south-eastern shores

of False Bay, Zululand, St Lucia Formation, Late Santonian.

Material

Paratypes are SAS-H126/1, H126/2, H126A?/11, H126B/1, H126B/2,

H126B/3a, H126E/1, H127B/1, Z1144—Z1147, Z1822, Z1869-Z1871, Z1881,

Z1952, Z1952A-E, Z2054, Z2058, Z2199, SAM—PCZ5884, PCZ5886, all from

locality 105, south-eastern shores of False Bay, Zululand, St Lucia Formation,

Santonian III to Campanian I; and SAM-5492, and SAS-Z353 from an

unknown locality near Umkwelane Hill, probably locality 14, St Lucia Forma-

tion, Santonian to Campanian. The letter after specimens with catalogue

numbers beginning with H126 denotes the horizon at locality 105 (see Fig. 130).

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

H126E/1 91,0 29,0(31,9) 37,0(40,4) 0,78 31,5(34,6) 23 37

Z1146 92,7 30,3(32,7) 39,9(43,0) 0,76 27,6(29,7) 23 35

Z1145 133,0 45,0(33,8) 55,0(41,4) 0,82 50,0(37,6) 19 31

H126B/2 117,0 36,0(30,8) 44,0(37,6) 0,82 43,0(36,8) 13x2 26

Z1952 145,0 45,0(31,0) 57,0(39,3) 0,79 55,0(37,9) 24 28

Z1869 150,0 49,0(32,6) —«62,0(41,3) 0,79 55,0(36,7) 13 oy

Z2054 153,5 43,0(28,0) 59,0(38,4) 0,72 59,0(38,4) 24 33

Z1952B 180,0 57,0(31,7) 67,0(37,2) 0,85 69,0(38,3) 13x2 30

Z1844 at 180,0 52,0(28,9) _ 67,0(37,2) 0,78 68,0(37,8) 15x2 30

at 76,0 26,5(34,9) 34,0(44,7) 0,78 27,5(36,2) 14 36

Z1870 180,0 62,0(34,4) 70,0(38,9) 0,89 71,0(9,4) 24 26

H126B/3 187,0 56,0(29,9) 73,0(39,0) 0,77 69,0(36,9) 18 28

Z2199 205,0 58,0(28,3) —-75,5(26,8) 0,77 83,0(40,5) 30 30

Z1822 261,0 75,0(28,7) _ 94,0(36,0) 0,79 LOMOGSaniaeaD 24

PCZ5884 263,0 76,0(28,9) 97,0(36,9) 0,78 97,0(36,9) —_ —

Z1881 230,0 62,0(26,9) 79,0(34,3) 0,78 88,0(38,3) 29 —

Z353 236,0 63,0(26,7) 90,0(38,1) 0,70 90,0(38,0) 26 38

Diagnosis

Extremely variable, but basically moderately involute, with umbilical

diameter of about 35 to 40 per cent in the adult stage, in juvenile specimens less.

Whorl section higher than wide, with maximum costal width at the lateral (2)

tubercle, or, infrequently in juvenile specimens, at umbilical edge. Umbilical

wall varies from rounded to near-vertical to overhanging. Ornament varies

CRETACEOUS FAUNAS FROM SOUTH AFRICA 215

Fig. 164. Texanites soutoni natalense ssp. nov. Holotype SAS—H126B/3. x 0,75.

from weak to strong. Some specimens tend to develop a smooth Submortoni-

ceras-like ornament on the inner phragmocone whorls, followed by normal

Texanites ornament on the outer phragmocone whorls. The umbilical (1)

tubercles point inward, the lateral (2) tubercles are clavate on the inner whorls,

but tend to become radially elongated on the outer whorls, and may be very

prominent. The submarginal, marginal and external (3-5) tubercles are clavate

throughout. Ribs on body chamber may curve slightly forward over the flanks,

with oblique, prorsiradiate extensions over the umbilical wall. Bifurcations and

216 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 165. Texanites soutoni natalense ssp. nov. Holotype SAS-H126B/3. x 0,9.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 217

Fig. 166. Texanites soutoni natalense ssp. nov. Paratype SAS-Z2199. x 0,67.

intercalations occur frequently on the inner whorls, but becume scarcer on the

outer whorls. Suture is of the normal collignoniceratid pattern, but with wide,

open lateral lobe (L) and U,, tending to become minutely frilled in some speci-

mens (Fig. 185).

Description

Texanitids occur abundantly along the south-eastern shores of False Bay,

Zululand, at locality 105, a steep cliff-face approximately 10 m high (see p. 173,

218 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 130). A few specimens from Umkwelane Hill are also conspecific with this

assemblage.

The material is extremely variable and hardly two specimens are alike.

Differences are restricted mainly to strength of ornament at comparable

diameters, and relative proportions. For descriptive purposes, three morpho-

logical varieties may be recognized: a typical form, an inflated form, and a

compressed form. Differences between these three varieties may be slight and

boundaries gradational, and, lacking precise stratigraphic control, are probably

predominantly isochronous. In lieu of long descriptions the extent of variation

will be illustrated as far as possible.

Forma typica

Apart from the holotype, SAS—H126B/3 (Figs 164-165), specimens to be

referred to the typical form are SAS—Z2199 (Figs 166-167A), SAS—H126B/1,

SAS-H126B/2 (Fig. 168), SAS—H126B/3a (Fig. 169), SAS—Z1952 (Figs 170-171), -

SAS-Z1144 (Fig. 172) and SAM-5492 (Fig. 173). These specimens all have

inner whorls with weaker ornament than the outer whorls, but details differ

considerably. Thus SAS—H126B/3a (Fig. 169) has relatively coarser and more

prominent ornament on the inner whorls at comparable diameters than the

holotype, SAS-—H126B/3 or SAS—H126B/2, even though they all occur within

the same horizon at locality 105. SAS—Z1144 differs from the rest of the speci-

mens in having abundant weak, bifurcating ribs on the inner whorls. One

fragment, with part of the body chamber preserved, SAS—H126/2 (Fig. 174),

with weakened but still visible ornament, may possibly belong to the typical

form. None of the specimens has the complete body chamber preserved.

Var. inflata

Specimen SAS-Z1870 (Figs 175-176), and to a lesser extent SAS—Z1822

(Figs 177-178) differ from the rest of the material in being much more inflated

and in having a smaller umbilical diameter, and may be referred to as var. inflata.

This variety also differs from the typical form in lacking smooth or weaker

ornamented inner whorls. Tuberculation here persists on part of the body

chamber preserved in SAS—Z1879 (Fig. 175). Transitions to the typical form

occur via SAS—H126B/2 (Fig. 168).

Var. compressa

Two specimens, SAS—Z1881 (Figs 179-180B) and SAS—Z353, differ from

the others in being more laterally compressed and in having weaker ornament

throughout, and may be referred to as var. compressa. As far as preservation

permits examination, a smooth inner stage appears not to be present.

Juvenile specimens

A number of juvenile specimens, SAS—Z1146-Z1147, SAS—Z1871, SAS-—

Z1952E, SAS-—H126E/1, SAS-H127B/1, and SAM-PCZ5886, and, possibly,

CRETACEOUS FAUNAS FROM SOUTH AFRICA 219

A B

Fig. 167. A. Texanites soutoni natalense ssp. nov. Paratype SAS—-Z2199. x 0,76. B. Texanites

presoutoni natalense ssp. nov. Paratype SAM-PCZ5885. x 0,72.

220 ANNALS OF THE SOUTH AFRICAN MUSEUM

NMB-D1320 are also referable to this species plexus, although positive refer-

ence to any of the above varieties is not possible. Variation in respect of strength

of ornament and whorl section is as considerable as in the adult population.

Specimens SAS—H127B/1 (Fig. 183B) and SAS—H126E/1 (Fig. 181B) suggest

that the specimens with more compressed Submortoniceras-like whorls occur

higher up in the sequence than those with more inflated whorl sections. Two

sets of specimens with similar relative proportions at equal diameters,

SAS-Z1146-Z1147, SAS-Z1871, SAS-H126E/1, and SAS-—Z1952E, SAS-

H127E/1, SAM-PCZ 5886 respectively, again illustrate the variation in strength

of ornament (Figs 181-183), NMB-—D1320 is more inflated than any of the

other juvenile specimens, and may possibly belong to another species.

Fig. 168. Texanites soutoni natalense ssp. nov. Paratype SAS—H126B/2. Typical form.

x 0,89.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 221

Interrelationships of varieties

The majority of specimens in the present collection belong to the typical

form, whereas the other two varieties are poorly represented. Due to lack of

sufficient stratigraphic data, the temporal relationship of the different varieties

is not very clear. We know only that the typical Submortoniceras forms are

youngest, and that those forms with smooth Submortoniceras-like inner whorls

Fig. 169. Texanites soutoni natalense ssp. nov. Paratype SAS—H126B/3a. Typical form.

x 0,82.

222 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 170. Texanites soutoni natalense ssp. nov. Paratype SAS—Z1952. Typical form. x 1.

first occur in Bed B at locality 105. Suggested lines of development are outlined

in Figure 132.

Submortoniceras woodsi natalense ssp. nov. may be derived protero-

genetically from 7. soutoni natalense forma typica; the inner smooth stage is

retained for progressively longer periods of growth, accompanied by a simul-

taneous reduction of umbilical width and compression. Var. inflata appears to

be sterile. As in T. soutoni soutoni, it seems possible to derive a widely umbilicate,

CRETACEOUS FAUNAS FROM SOUTH AFRICA 223

Fig. 171. Texanites soutoni natalense ssp. nov. Paratype SAS—Z1952. Typical form. x 1.

224 ANNALS OF THE SOUTH AFRICAN MUSEUM

compressed submortoniceratine form such as SAS—Z1762 (Fig. 184) from

var. compressa. As in the nominate subspecies, this compressed lineage also

seems to be a dead-end.

Discussion

This subspecies is very variable, and should be interpreted in terms of

consanguinity of characteristics predominating in the majority of specimens

rather than narrowly defined characteristics present only in the holotype.

The stratigraphic occurrence of typical specimens in Bed B at locality 105

(Fig. 130), immediately overlying Bed A containing T. presoutoni natalense,

may suggest genetic relationship between the two species, as here assumed

(Fig. 132). Similarly, the relatively higher stratigraphic occurrence of Sub-

mortoniceras woodsi natalense again seems to support genetic relationship

between the two.

T. soutoni natalense ssp. nov. is of age similar to the predominantly Pondo-

land subspecies 7. soutoni s.s. It is associated with an ammonoid fauna con-

sisting of Hauericeras gardeni, Pseudoschloenbachia umbulazi and varieties,

‘Heteroceras’ amapondense and Pseudophyllites latus (Fig. 130), similar to

that of Umzamba Cliff (Klinger & Kennedy in press) but in much reduced

numbers. Coarsely ornamented forms lacking the inner whorls, as SAS—Z1952

(Fig. 170), are indistinguishable from inflated forms of 7. soutoni s.s. Current

evidence seems to suggest that 7. soutoni s.s. flourished in the shallow water

of the transgressive sequence ranging from Umkwelane Hill in the north to

Pondoland in the south, whereas 7. soutoni natalense inhabited the deeper

part of the sedimentary basin in the False Bay area. Intermingling took place

in the vicinity of Umkwelane Hill. In this regard T. soutoni soutoni and T. soutoni

natalense may qualify for subspecific status in the biological sense.

Major differences between T. soutoni soutoni and T. soutoni natalense are:

the presence of a relatively smooth Submortoniceras-like stage on the inner

whorls of some specimens, followed by more coarsely ornamented Texanites-

like ornament on the outer whorls; generally smaller size and the presence of a

wide, shallow lateral and umbilical lobe; and more inflated whorl section in

T. soutoni natalense.

The juvenile specimens described above (Figs 181-183), may be compared

with a number of figured texanitid species, but specific differentiation at these

diameters is impossible, e.g.:

Submortoniceras woodsi (Spath) (see below).

Submortoniceras tequesquitense Young (see especially Young 1963, pl. 51

(fig. 1), pl. 28 (fig. 1)).

Texanites texanus gallica (in Young 1963, especially pl. 38 (fig. 3)).

Texanites hourcgi Collignon (Collignon 1948, pl. 7(1) (fig. 1)) ete.

The adult stages of these species, however, usually reveal the differences

with T. soutoni natalense.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

lform. X 0,89.

ica

Typ

Fig. 172. Texanites soutoni natalense ssp. nov. Paratype SAS-Z1144

226 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 173. Texanites soutoni natalense ssp. nov. Paratype SAM-—5492. Typical form. This is the

specimen described by Spath (1921: 235) as Mortoniceras sp. aff. soutoni. X 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 227

Fig. 174. Texanites soutoni natalense ssp. nov. Paratype SAS—H126/1. Specimen with part

of the body chamber preserved; probably belonging to the typical form. Note continuation

of pentatuberculate ornament on body chamber section. x 0,57.

228 ANNALS OF THE SOUTH AFRICAN MUSEUM

SAS-Z1881 (Fig. 179), here named var. compressa, is remarkably similar

to the holotype of Texanites shiloensis (see Young 1963, pl. 46 (fig. 1)) in having

a more or less Submortoniceras-like ornament on the outer whorl. As shown

below, relative proportions are similar.

Dimensions

D Wb Wh U Int. Ext.

UT-1986 275,0 — (32,0) (40,0) 31 31

(T. shiloensis)

Z1881 230,0 62,0(26,9) 79,0(34,3) 88,0(38,3) 30 —

Fig. 175. Texanites soutoni natalense ssp. nov. Paratype SAS-Z1870. Variety inflata. x 0,68.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 229

Fig. 176. Texanites soutoni natalense ssp. nov. Paratype SAS—Z1870. Variety inflata. x 0,68.

230 ANNALS OF THE SOUTH AFRICAN MUSEUM

‘YW -

Fig. 177. Texanites soutoni natalense ssp. nov. Paratype SAS—Z1822. Variety inflata. x 0,52.

The holotype of T. shiloensis has a measured diameter of 275 mm, and

the only apparent difference between the two, apart from size, is the finer,

denser ribbing with frequent intercalations on the inner whorls. In addition to

being very similar to the present material, T. shiloensis is of further interest in

that it grades vertically into Submortoniceras tequesquitense. As far as relative

size is concerned, 7. shiloensis is close to the compressed variety of T. soutoni

S.S., €.g. specimen SAM-7077 (Fig. 146), but in the weakened ornament is

closer to T. soutoni natalense, e.g. SAS—Z1881 (Fig. 179).

CRETACEOUS FAUNAS FROM SOUTH AFRICA 231

Given sufficient material, it may eventually prove possible to refer T. shilo-

ensis and S. tequesquitense to the group of T. soutoni-S. woodsi at subspecific

level, as a North American population.

Occurrence

Upper Santonian of Zululand.

Genus Submortoniceras Spath, 1921

(= Butticeras Anderson, 1958

?=Jimenesites Carrasco, 1967

?= Antsirasirella Collignon, 1966

?= Ankilizatella Collignon, 1970)

Type species

Mortoniceras woodsi Spath, 1921, by original designation of Spath.

Diagnosis

Coiling generally involute, with whorls increasing rapidly in size. Penta-

tuberculate from a relatively early stage, but there is a distinct tendency towards

loss of lateral ornament on the outer whorls. Whorl section generally com-

pressed, especially in the later species.

Discussion

Intraspecific variation in Submortoniceras species is bewildering, even by

Texanites standards as applied in the South African material. The large number

of seemingly endemic species probably results from the difficulty encountered

in trying to compare species from different areas.

The species below are those referred to Submortoniceras in the literature.

A great number of these are probably synonymous, as will be discussed below.

S. angusteumbilicatum Collignon (1948: 105, pl. 16 (figs 1-1b, 2—2a)) from the

Middle Campanian of Madagascar.

S. behamotrense Collignon (1970: 46, pl. 626 (figs 2318—2320)) from the Middle

Campanian of Madagascar.

S. candelariae Young (1963: 102, pl. 56 (figs 1, 3-4), pl. 60 (fig. 8), text-figs 20b,

28af, 29ae, 34af) from the Lower Campanian of the Gulf Coast of North

America.

S. chicoense (Trask) (1856: 92, pl. 2 (fig. 1)) from the Lower Campanian of

California, Texas, and James Ross Island Group.

S. collignoni Shimizu, 1935 (=M. woodsi in Collignon 1932: 35, pl. 5 (fig. 2-2b)

text-fig. 19) from the Middle Campanian of Madagascar.

S. condamyi Collignon (1932: 36, pl. 5 (fig. 3-3b), text-fig. 20) from the Lower

Campanian of Madagascar and South Africa.

S. debile Collignon (1948: 103, pl. 19(13) (fig. 3-3a)) from the Middle Cam-

panian of Madagascar.

S. dubium Collignon (1948: 97, pl. 18(12) (fig. 3-3b)) from the Middle Cam-

panian of Madagascar.

252 ANNALS OF THE SOUTH AFRICAN MUSEUM

S. elimatum Collignon (1948: 104, pl. 20(14) (fig. 2-2a)) from the Lower Cam-

panian of Madagascar.

S. franiattae Collignon (1970: 43, pl. 626 (fig. 2316)) from the Middle

Campanian of Madagascar.

S. imlayi Collignon (1948: 101, pl. 20(16) (fig. 3-3a)) from the Middle Cam-

panian of Madagascar.

S. johannisludovici Collignon (1970: 47, pl. 628 (fig. 2321)) from the Middle

Campanian of Madagascar.

S. mariscalense Young (1963: 104, pl. 59 (fig. 3), pl. 60 (figs 1, 4-6), text-fig.

14bf) from the Lower Campanian of the Gulf Coast of North America.

S. pauper Collignon (1948: 103, pl. 18 (fig. 2-2a)) from the Lower and Middle

Campanian of Madagascar.

S. piveteaui Collignon (1948: 102, pl. 7(1) (fig. 6-6b), pl. 19(13) (fig. 2-2a))

from the Middle Campanian of Madagascar.

S. punctatum Collignon (1948: 99, pl: 18(12) (fig. 1-1a)) from the Lower Cam-

panian of Madagascar.

S. rarecostum Collignon (1948: 101, pl. 20(14) (fig. 3-3a)) from the Middle

Campanian of Madagascar.

S. renniei Collignon (1948: 106, pl. 17 (fig. 1)) from the Lower Campanian of

Madagascar.

S. rugetae Collignon (1969: 189, pl. 593 (fig. 2242)) from the Lower Campanian

of Madagascar.

S. sancarlosense Young (1963: 100, pl. 55 (figs 1-4), pl. 62 (fig. 3), text-figs 20g,

27d) from the Lower Campanian of the Gulf Coast of North America.

S. spathi Collignon (1948: 106, pl. 20(14) (fig. 1-la)) from the Middle Cam-

panian of Madagascar.

S. tenuicostulatum Collignon (1948: 96, pl. 19(13) (fig. 1-1b)) from the Lower

and Middle Campanian of Madagascar.

S. tequesquitense Young (1963: 97, pl. 28 (fig. 1), pl. 42 (figs 1-2), pl. 44 (figs 4-5),

pl. 51 (figs 1-2), pl. 52 (figs 1-4), pl. 57 (fig. 4), pl. 70 (fig. 1), text-figs 12b,

28b) from the Lower Campanian of the Gulf Coast of North America.

S. uddeni Young (1963: 105, pl. 59 (figs 1-2, 4-9), pl. 60 (figs 2-3, 7, 9-10),

text-figs 14de, 28c) from the Lower Campanian of the Gulf Coast of

North America.

S. vanuxemi (Morton) (1830: 244, pl. 3 (figs 3-4)) from the Campanian of

North America.

S. vandaliaense Young (1963: 102, pl. 55 (figs 6-7), text-fig. 26a) from the

Lower Campanian of the Gulf Coast of North America.

S. woodsi (Spath) (1921: 223, pl. 21 (fig. la—d)) from the Lower Campanian of

Madagascar and South Africa.

‘Butticeras’ buttense Anderson (1958: 272, pl. 53 (figs 3—-4)) from the Lower

Campanian of the Pacific Coast of America.

‘Butticeras’ studleyi Anderson (1958: 272, pl. 51 (figs 3—-4)) from the Lower

Campanian of the Pacific Coast of America.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 233

Fig. 178. Texanites soutoni natalense ssp. nov. Para-

type SAS-Z1822. Variety inflata. x 0,6.

234 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 179. Texanites soutoni natalense ssp. nov. Paratype SAS—Z1881. Variety compressa.

x 0,59.

Anderson (1958: 272) introduced the genus Butticeras, with type species

Butticeras buttense, for a group of small ammonites in which the keel is lost in

maturity, the venter becomes rounded, and all lateral tuberculation is lost

except the umbilical and external rows. Matsumoto (1959: 132) speculated that

Butticeras may represent an extreme form of Submortoniceras chicoense, though

not definitely committing himself. Consequently, Butticeras should be regarded

as a junior synonym of Submortoniceras. This appears to be reasonable pro-

cedure, as subdivision of such a variable genus should be limited to the absolute

CRETACEOUS FAUNAS FROM SOUTH AFRICA 235

minimum. On this basis it would also be advisable to include the monotypical

subgenus S. (Antsirasirella) Collignon (type species S. (Antsirasirella) stellata

Collignon (1969: 201, pl. 599 (fig. 2252)) in the strict synonymy of Submortoni-

ceras. S. (Antsirasirella) stellata has extremely reduced lateral ornament,

similar to Butticeras, but has a flattened venter in the adult stage, thus differing

from the latter. For the present it is probably best to consider S. (Antsirasirella)

as merely representing an extreme development of the attenuation of ornament

in Submortoniceras.

The monospecific subgenus Texanites (Ankilizatella) Collignon (type

species T. (Ankilizatella) ankilizatensis Collignon 1970: 50-51, pl. 629 (figs

2322-2325)) from the Middle Campanian of Madagascar is probably better

placed in Submortoniceras than in Texanites. The type (and only) species has a

compressed disc shape and smooth outer whorls as in Submortoniceras, but a

wide umbilicus as in Texanites. The compressed section and lack of ornament

on the outer whorls are more characteristic of Submortoniceras than of Texa-

nites. As far as umbilical width is concerned, Ankilizatella possibly connects

with Submortoniceras s.s. via S. behamotrense, S. renniei and S. mariscalense;

especially the former.

Submortoniceras is easily distinguished from most texanitine genera by

virtue of the generally tight coiling and attenuation of ornament on the outer

whorls. Difficulties arise, however, in the Middle Campanian in distinguishing

between Submortoniceras and Menabites (Delawarella), especially when the

inner whorls are lacking. Matsumoto (1959: 125-6) preferred to refer M. (Dela-

warella) as a subgenus to Submortoniceras rather than to Menabites, but later

(Matsumoto 1970: 299) retracted this view. From a phylogenetic point of view,

however, this former procedure cannot be accepted (see also Young 1963: 39).

M. (Delawarella) typically has a multiplied row of external tubercles, charac-

teristic of Menabites s.1., and is often trituberculate to a large diameter. How-

ever, when lateral ornament is attenuated, it is difficult to see whether the greater

number of external tubercles is due to the original multiplication of Menabites

s.l., or due to abundant bifurcations and intercalations of Submortoniceras.

Young’s (1963: 76) key to the classification of the Texanitinae is of little use

in this case. Despite this example of isochronous homoeomorphy, Submortoni-

ceras and Delawarella should be maintained separate, because of different

phylogenies and ontogenetic development.

Both Young (1963: 39) and Matsumoto (1970: 239) agree in deriving

Submortoniceras from Texanites, a view corroborated by the South African

material. As described above, S. woodsi is derived gradually from T. soutoni

through reduction of umbilical diameter and effacement of the ornament on

the outer whorls. Submortoniceras appears to be a dead-end in texanitine

development, and the last Submortoniceras species occur in the Middle Cam-

panian of Madagascar.

As is seen from the list of species referred to the genus, the majority seem

to be endemic to the regions from which they were first described. None of the

236 ANNALS OF THE SOUTH AFRICAN MUSEUM

SS :

hep

Gj My

WH hy,

UY);

Fig. 180. Texanites soutoni natalense ssp. nov. A. Paratype SAS-—Z1144.

Typical form. x 0,6. B. Paratype SAS—Z1881. Var. compressa. X 0,69.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 237

Fig. 181. Texanites soutoni natalense ssp. nov. Juvenile paratypes. A. Z1147. B. SAS-H126E/1. x 1.

238 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 182. Texanites soutoni natalense ssp. nov. Juvenile paratype SAS—Z1146 with much

attenuated ornament. x 1.

species described from Madagascar is known to occur definitely in North

America and vice versa. This causes one to think that Submortoniceras is either

restricted to certain geographic areas with little or no intermingling between

the populations, but highly successful and populous as far as number of species

are concerned, or it is an extremely successful group with limited speciation

potential but wide dispersion and tremendous intraspecific variation. Analysis

of the South African material and work by Matsumoto (1959) seem to suggest

the latter. In his examination of S. chicoense, Matsumoto (1959) was able to

recognize three morphological variants, forma «, B and y, which, by traditional

systematic procedure, would probably qualify for separate specific rank. He

found, however, that there was a continuous gradation from one form to the

other, and that the different types may even occur in the same nodule. In

addition, Matsumoto tentatively compared the Californian specimens with

some of the numerous species of Submortoniceras described by Collignon

(1948) from Berere, Madagascar. S. piveteaui resembles S. chicoense forma a,

S. imlayi is close to forma B, and S. angusteumbilicatum and S. spathi are close

CRETACEOUS FAUNAS FROM SOUTH AFRICA 239

Fig. 183. Texanites soutoni natalense ssp. nov. Juvenile paratypes. A. SAM-—PCZ5886.

B. SAS-H126B/1. C. SAS—Z1952. x 1.

240 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 184. Texanites soutoni natalense ssp. nov. Paratype SAS—Z1762. Compressed, widely

umbilicate variety probably derived from var. compressa (see also Fig. 132). x 0,48.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 241

Fig. 185. Texanites soutoni natalense ssp. nov. Suture lines of paratypes. A. SAS-Z1881.

B. SAS-Z1146. C. SAS-Z358. D. SAS—Z1871. E. SAS—Z1147.

to forma y of S. chicoense. Even though Matsumoto would not definitely

commit himself to synonymizing the species without having seen the Mada-

gascar species in their stratigraphic context, it is gratifying to see that the

‘endemic’ gap between the North American and Madagascar species can be

narrowed. :

The South African material is as variable as S. chicoense, and is here

referred to the two existing species S. woodsi and S. condamyi. As will be seen

in the systematic descriptions below, ornament and suture are extremely

variable. Specimens with smooth inner whorls occur at the same stratigraphic

level as heavily ornamented ones, and are connected by transitions. In the South

African material, ornament is partially associated with geographic location,

suggesting that ornament alone is of very little systematic value in the classi-

fication of Submortoniceras species. There appears to be a definite trend in the

South African Submortoniceras population towards progressive tighter coiling

and compression of the whorls. At present the significance of this is not clear,

242 ANNALS OF THE SOUTH AFRICAN MUSEUM

but the authors would suggest that it may be connected in some way to a slightly

deeper water habitat or more active way of life. A similar trend is found in the

Gulf Coast deposits of North America where Texanites shiloensis grades

upward into Submortoniceras tequesquitense (see Young 1963: 90).

Consequently, degree of involution is here considered of maximum value

in classifying Submortoniceras species.

This all suggests that the number of species listed above may be greatly

reduced, provided sufficient detailed stratigraphic data and material become

available.

Occurrence

Submortoniceras species occur profusely in the Lower and Middle Cam-

panian of Madagascar, and in slightly smaller numbers in the Upper Santonian—

Lower Campanian of South Africa, the Lower Campanian of the Pacific Coast

and Gulf Coast areas of North America, and sporadically in British Columbia.

A single specimen of S. chicoense was reported from the Sub-Antarctic James

Ross Island Group. Young (1963: 39) refers Redtenbacher’s (1873) Ammonites

propoetidum to the genus Submortoniceras, but the authors would rather place

this species in Gauthiericeras, as was done by Reyment (1958), or in Zuluiceras

Van Hoepen.

Submortoniceras woodsi s.1. (Spath, 1921)

Figs 186-199, 200B

Mortoniceras woodsi Spath, 1921: 232, pl. 21 (fig. la—d). Non Besairie, 1930: 637, pl. 67 (fig. 1)

(=S. angusteumbilicatum Collignon). ?Non Collignon, 1932: 35, pl. 5 (fig. 2-2b) (=S.

collignoni Shimizu).

Mortoniceras vanuxemi (Morton): Spath, 1921: 308, pl. 23 (fig. 4a—4b).

Submortoniceras woodsi (Spath): Collignon, 1948: 43. Kennedy & Klinger, 1973: 103, pl. 2

(fig. 3), pl. 3 (figs 2-3), pl. 5 (fig. 3).

Type

Holotype is SAM-5451 (Fig. 186) from an unknown horizon at Umkwe-

lane Hill near Mtubatuba, Zululand, St Lucia Formation, Santonian to

Campanian.

Material

SAS-Z1875, Z1138, Z1893, SAM-—PCZ5884, PCZ5883, all from locality

105, south-eastern shores of False Bay, St Lucia Formation, Upper San-

tonian to Lower Campanian; SAM-PCZ5896 and BMNH-C81489, from

Umkwelane Hill, near locality 14, St Lucia Formation, Upper Santonian

to Lower Campanian; SAM-—PCZ5897, locality 6, Richards Bay, St Lucia

Formation, Upper Santonian to Lower Campanian; SAM-—PCP5716, Bed A3

locality 1, Umzamba Formation, Upper Santonian to Lower Campanian;

BMNH-C81487, locality 74, Santonian III; and BMNH-C81488 from the

same locality, St Lucia Formation, Campanian I.

243

CRETACEOUS FAUNAS FROM SOUTH AFRICA

<ele

iceras woodsi woodsi. Holotype SAM-5451

Submorton

. 186.

Fig

244 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

Holotype 78,0 30,5(39,1) 38,5(49,3) 0,79 DSA oe 35

Z1875 325,0 — 115,0(35,4) — —_ 29 30

Z1138 294,0 80,0(27,2) 105,0(35,7) 0,76 115,0(39,1) 31 35

at 198,0 57,5(29,0) 76,5(38,6) 0,75 69,0(34,9) 24 41

PCZ5897 226,0 -74,0(32,7) —-92,0(40,7) 0,80 74,0(32,7) 25 34

PCZ5884 262,0 76,0(29,0) 100,0(38,2) 0,76 90,0(34,4) 25 30

PCP5716 270,0 90,0(33,3) 108,0(40,0) 0,83 87,0(32,2) 28 37

Z1893 280,0 84,0(30,0) 108,0(38,7) 0,78 102,0(36,5) 25 34

Diagnosis

Species with umbilical width of the order of c. 35 per cent of total diameter.

Ornament generally weakens from inside outwards on phragmocone, but

specimens with virtually smooth inner whorls occur. In some specimens lateral

ornament on body chamber is strong.

Description

Coiling is generally involute with an umbilical width of the order of

c. 35 per cent of the total diameter, but may be as high as 39 per cent, connect-

ing with Texanites soutoni s.l., as on the outer whorls of SAS—Z1138 (Fig. 187).

The whorl section is higher than wide throughout, with a steep to over-

hanging umbilical wall (Figs 197, 200B), weakly inflated flanks on the inner

whorls, but more inflated on the late phragmocone and on the body chamber.

Ornament on the phragmocone varies considerably, from virtually smooth,

barring slight radial striations indicative of weak ribbing in SAS—Z1875 (Figs

188-189) and SAS—Z1138 (Figs 187, 190), through weakly tuberculate as in

SAM-PCZ5884 (Fig. 191), to coarsely ornamented in SAM-—PCZ5897 (Fig. 192),

SAS-Z1893, and SAM-—PCP5716 (Fig. 193). All ornament, where present on

the inner whorls, weakens toward the middle part of the phragmocone, but

thereafter becomes stronger again towards the later part of the phragmocone

and the body chamber. Very strong ribbing is developed in SAS—Z1138 (Fig. 187)

on the body chamber, containing the full complement of pentatuberculate

ornament. Lateral tuberculation is also still visible on the body chambers of

SAS-Z1875 (Fig. 188), SAM-—PCZ5896 and SAM-PCZ5897 (Fig. 192). SAM-—

PCP5716 (Fig. 193) has a few bifurcating ribs on the body chamber as in Texa-

nites soutoni S.S.

The suture line is variable, ranging from wide, short lobes to long and

narrowly splayed lobes (Figs 187, 190-194).

Discussion

The authors have previously commented on the difficulty in interpreting

this species (Kennedy & Klinger 1973: 103). Spath’s original figures are poor,

his description is too brief and stratigraphic data are lacking.

The holotype of Mortoniceras woodsi, here refigured as Figure 186, is

based on an incomplete inner whorl of a specimen c. 80 mm in diameter, from

CRETACEOUS FAUNAS FROM SOUTH AFRICA 245

Fig. 187. Submortoniceras woodsi natalense ssp. nov. Paratype SAS—Z1138. Specimen with

wide umbilicus, connecting to Texanites soutoni. x 0,5.

an unknown horizon at Umkwelane Hill. The innermost whorls up to a dia-

meter of c. 50 mm are incomplete, and only the ventral half of the flanks and

the venter are preserved, showing strong marginal (4) and external (5) tubercles,

weaker submarginal (3) tubercles, and an entire keel. The last third of a whorl

preserved on the holotype shows very faint ribs bifurcating from strong inward

leaning umbilical (1) tubercles, with very faint lateral (2) tubercles, slightly

246 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 188. .Submortoniceras woodsi natalense ssp. nov. Holotype SAS-Z1875. x 0,4.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 247

Fig. 189. Submortoniceras woodsi natalense ssp. nov. Holotype SAS—Z1875. Close-up

of inner whorls to show smooth flanks.

248 ANNALS OF THE SOUTH AFRICAN MUSEUM

A B

Fig. 190. Submortoniceras woodsi natalense ssp. nov. Paratype SAS—Z1138. Illustrating

weak ornament on inner whorls. x 1.

stronger submarginal (3) tubercles and visible, but much weaker than previously

marginal (4) and external (5) tubercles.

These scant data, combined with our knowledge of the extreme intra-

specific variation in Submortoniceras chicoense, as shown by Matsumoto (1959),

or Texanites soutoni (Klinger & Kennedy herein p. 189), render interpretation

of Submortoniceras woodsi impossible in terms of the holotype alone. Conse-

CRETACEOUS FAUNAS FROM SOUTH AFRICA 249

Fig. 191. Submortoniceras woodsi natalense ssp. nov. Paratype PCZ5884. Specimen with

weak ornament on inner whorls. x 0,57.

quently the authors interpret the species on the basis of topotype and more or

less isochronous material.

As far as attenuation of ornament on the flanks is concerned, the holotype

agrees well with the inner whorls of SAS—Z1875 (Fig. 188) or SAS—Z1138

(Fig. 187). The sutures, however, are completely different. The holotype has a

suture with long and narrow lobes (Fig. 194A) as compared to the broad and

250 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 192. Submortoniceras woodsi woodsi (Spath, 1921). SAM-—PCZ5897. Specimen from

Richards Bay with strong ornament on inner whorls. x 0,65.

CRETACEOUS FAUNAS FROM SOUTH AFRICA De |

Fig. 193. Submortoniceras woodsi woodsi (Spath, 1921). SAM-—PCPS5716. Specimen

from Umzamba with extremely strong ornament. x 0,47.

short lobes of the latter two specimens (Fig. 195) and shows strong resemblance

to Texanites soutoni s.s. in this respect. Topotype material from Umkwelane Hill

figured by the authors (Kennedy & Klinger 1973, pl. 2 (fig. 3)) and a magnificent

specimen from nearby at Richards Bay, SAM—PCZ5897 (Fig. 192), have

similar long and narrow lobes, but distinct lateral ornament on the inner

whorls. Thus, as in the case of T. soutoni, we are faced with two apparently

different populations; one with smooth inner whorls and the other with variable

ornament on the inner whorls. The specimens with smooth inner whorls

generally have wide, short lobes and saddles whereas the specimens with

252 ANNALS OF THE SOUTH AFRICAN MUSEUM

B C

Fig. 194. Submortoniceras woodsi woodsi (Spath, 1921). Suture lines. A. Holotype SAM-—S5451.

B-C. SAM-PCZ5897.

coarsely ornamented inner whorls generally have long, thin lobes, but excep-

tions do occur. SAS—Z1893 (Fig. 196) has coarse ornament on the inner whorls

but wide, open lobes. Comparable variation in suture line has been reported in

S. chicoense by Matsumoto (1959: 129). Specimens with wide, open, blocky

sutural elements appear predominantly in the False Bay region of Zululand,

whereas the specimens with narrow, thin lobes and generally strong lateral

ornament occur primarily in the southern regions of Umkwelane Hill, Richards

Bay, Durban, and Pondoland.

Thus, in conformity with the procedure followed by the authors in T. sou-

toni s.1. and T. presoutoni s.l., S. woodsi may be divided into two subspecies,

S. woodsi woodsi (Spath) (holotype is SAM-—5451, Fig. 186) and S. woodsi

CRETACEOUS FAUNAS FROM SOUTH AFRICA 253

natalense ssp. nov. (holotype is SAS—Z1875, Fig. 188), though bearing in mind

that the dividing line here is extremely thin.

The holotype of S. woodsi was fitted into a dwarfed body chamber fragment

from the Umkwelane Hill region. This chimera (Fig. 198) may possibly illus-

trate what the holotype of S. woodsi woodsi really looked like.

SAM-PCP5716 (Fig. 193) differs from the rest of the material in being

tightest coiled, with an umbilical diameter of 32 per cent, thus approaching

the limits of S. condamyi (described below), but still retaining a T. soutoni-

like ornament of the body chamber.

Differences between S. woodsi s.l., and S. condamyi and T. soutoni are

gradational, as outlined above (p. 177), and become indistinct in juvenile

specimens. Difficulties arise especially in distinguishing between juveniles of

T. soutoni natalense ssp. nov. with smooth whorls, e.g. SAS—Z1146 (Fig. 182),

and the holotype of S. woodsi. The latter appears to be more narrowly umbilicate

and has a more inflated whorl section. It thus appears as if acquisition of Sub-

mortoniceras characteristics (in this case involution and compression of whorl

section) takes place at varying and independent rates.

As the authors have pointed out previously (Kennedy & Klinger 1973:

103), S. woodsi may possibly be conspecific with a number of species described

from Madagascar. In view of the poor definition of S. woodsi in terms of the

holotype, and without being able to study the Madagascar specimens in their

exact stratigraphic context, all comparisons must be viewed with utmost care.

S. tenuicostulatum has a slightly more compressed whorl section, but a

comparable umbilical diameter (32-37%), and may possibly be a junior syno-

nym of S. woodsi. Differences given by Collignon (1948: 97) pertaining to density

of ribbing and spacing of the submarginal (3) and marginal (4) tubercles seem

rather trivial, and, in fact, the specimen of S. woodsi figured by the authors

from Durban (Kennedy & Klinger 1973, pl. 3 (fig. 2a-c)) (Fig. 199A-C) is

ONS me ac

iN Ry

ig om

’ Sao

\ ') CON et 5

'] ¢ = = = =

4 r ewan fm a=

= r) » --3 = =).

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— os an }) = = = 2am fF @ w= wo ==! ¢

- = = ~=-\- 52g.

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- fF FPF @ fr | = aoe) = -, oP PS @ @\o-)2 —- =s

ACK eS i frm Tae ects CONC

A as ( 4

a aoe Ca ser aes oe ES ae gas in eT eS

4 8 Sewer = - a

Fig. 195. Submortoniceras woods natalense ssp. nov. SAS-Z1138. Suture line. x 1.

254 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 196. Submortoniceras woodsi s.1. SAS—Z1893. Specimen with broad lobes and saddles,

but strong ornament on inner whorls. x 0,55.

295

CRETACEOUS FAUNAS FROM SOUTH AFRICA

iipehiiiiig,

Lh,

dla

Fig. 197. Submortoniceras woodsi natalense ssp

nov. A. PCZ5854

» PCZ5897.

x 0,63.

oth

x 0

256 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 198. Submortoniceras woodsi s.l. (Spath, 1921). Chimera consisting of dwarfed outer

whorl, partially septate, SAM-—PCZ5896 from Umkwelane Hill, with the holotype, SAM-5451

fitted inside. x 0,76.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 257

remarkably similar to that of S. tenuicostulatum figured by Collignon (1948,

pl. 19(13) (fig. 1-1b)). S. tenuicostulatum, however, appears to be of slightly

younger age, occurring in the Middle Campanian Zone of Pachydiscus gros-

souvrei of Madagascar, compared to the Upper Santonian and/or Lower

Campanian occurrence of S. woodsi in South Africa.

S. collignoni (=Mortoniceras (Submortoniceras) woodsi Collignon non

Spath) may possibly be included in the synonymy of S. woodsi. The specimen

figured by Collignon compares well with the inner whorls of S. woodsi natalense,

as does the suture line figured by Collignon (1932: 36, text-fig. 19).

S. punctatum retains ornament to a larger diameter than S. woodsi and

has an umbilical diameter transitional between that of S. woodsi and S. con-

damyi, and can probably be accommodated in either of these two species.

Of the Submortoniceras species described from Texas by Young (1963),

S. tequesquitense seems very closely allied if not conspecific with S. woodsi.

As far as relative proportions are concerned, dimensions of the two species

overlap. S. tequesquitense has an umbilical diameter of 31 to 36 per cent, a

reading of 41 per cent possibly being due to compression, and a Wb/Wh ratio

of 0,93 to 0,69 decreasing with size, compared with an umbilical width of 32

to 39 per cent and a Wb/Wh ratio of 0,76 to 0,83 in S. woodsi. Young compared

this species with S. tenuicostulatum, stating that it differed in having more

prominent tuberculation and less bifurcations than S. tenuicostulatum. Apart

from a slightly narrower whorl section, denser and more forwardly curved

costation, there seems to be little difference between S. tequesquitense and

S. woodsi. Another similarity between S. tequesquitense and S. woodsi is that

Young (1963: 98) suggested that S. tequesquitense could be derived from Texa-

nites shiloensis by caenogenesis, a situation comparable to that between S. woodsi

and 7. soutoni. Given more material, it may eventually prove possible to connect

the sequence of 7. shiloensis—S. tequesquitense to that of T. soutoni s.1.—S. woodsi

s.l. at subspecific level as a North American equivalent.

The fragmentary specimen from the north-western side of False Bay

described by Spath (1921: 308) as Mortoniceras vanuxemi probably also belongs

to the group of S. woodsi rather than S. vanuxemi, of which no typical examples

have as yet been found in Zululand. In view of the variation encountered in

the sutures of S. woodsi s.1., Spath’s (1921: 308) observation that the suture

line of this specimen was similar to that of S. woodsi and T. soutoni, but differed

on account of the terminations of the lateral lobe, poses no serious problem.

Occurrence

Upper Santonian to Lower Campanian of Zululand and Pondoland, and

rare in the Lower Campanian of Madagascar. Possible equivalents occur in

the Lower Campanian of Texas.

258 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 199. Submortoniceras woodsi woodsi (Spath, 1921). A-C. UN6566. D-E. UN6566.

(Specimens figured by the authors 1973, pl. 3 (fig. 2) and pl. 5 (fig. 3) from Durban.) x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 259

Fig. 200. A. Submortoniceras condamyi s.\. (Collignon, 1948). SAS—Z1880. x 0,7. B. Sub-

mortoniceras woodsi (Spath, 1921). (See Fig. 198.) x 0,8.

260 ANNALS QF THE SOUTH AFRICAN MUSEUM

Submortoniceras condamyi s.]. (Collignon, 1948)

Figs 200A, 201-209, 212-213

Mortoniceras condamyi Collignon, 1932: 36, pl. 5 (fig. 3-3b).

Mortoniceras (Submortoniceras) condamyi (Collignon): Collignon, 1938: 76.

Submortoniceras condamyi (Collignon): Collignon, 1948: 100, pl. 18(12) (fig. 2-2b), pl. 15.

Type

Holotype is the specimen figured by Collignon (1932, pl. 5 (fig. 3-3b)) from

the Lower Campanian of the environs of Berere, Madagascar.

Material

SAS-Z1140, Z1180, Z1952c, and SAM-PCZ5883, locality 105, south-

eastern shores of False Bay, Zululand, St Lucia Formation, Upper Santonian

to Lower Campanian; SAS—-A2084, SAS-76/1, SAS—76, Z1756, SAM—PCZ5892—

5894, all from locality 74, north-western shores of False Bay at Die Rooiwalle,

St Lucia Formation, Upper Santonian to Lower Campanian; and SAM-—

PCP5717, Bed A7 locality 1, Umzamba Estuary, Pondoland, Umzamba Forma-

tion, Santonian/Campanian Boundary. SAM—PCP5885 and NMB-D1191 are

from an unknown horizon at locality 1 at the Umzamba Estuary, Pondoland,

Umzamba Formation, Santonian to Campanian.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

Z1140 182,0 51,0(28,0) 68,0(37,4) 0,75 56,0(30,8) 13x2 17x2

SAS-76/1 199,0 56,0(28,1) 83,0(41,7) 0,67 65,0(32,7) 25 42

Z1952c 115,0 39,0(33,9) 52,0(45,2) 0,75 32,0(27,8) 22 38

A2084 195,0 57,0(29,2) 75,0(38,5) 0,76 67,0(34,4) 24 37

Z1180 215,0 54,0(25,1) 78,0(36,3) 0,69 70,0(32,6) — —

PCZ5893 147,0 47,0(31,9) 63,0(42,9) 0,74 46,0(31,3) 28 40

PCZ5892 141,0 47,0(33,3) 56,0(39,7) 0,84 53,0(37,6) — —

Description

The material is very variable, but may be diagnosed as being narrowly

umbilicate (c. 30%) with compressed whorl section and much attenuated orna-

ment throughout.

Coiling in the earlier stages is tighter than in the adult stage, c. 23 per

cent in SAS—Z1880 (Figs 201-202). SAM-—PCZ5892 (Fig. 203) differs from the

rest of the material in being much wider umbilicate, with an umbilical diameter

of 37,6 per cent, coarser ornamented throughout, and it connects with S. woodsi.

The whorl section is higher than wide throughout, with weakly inflated

flanks converging to a narrow venter (Figs 200A, 202B, 204A). Maximum

whorl breadth is near midflank or towards the dorsal third of the flanks. The

ratio of whorl breadth to whorl height is variable, as is the rounding of the

venter (Figs 200A, 204A).

Ornament on the inner and outer whorls varies from coarsely ornamented

to virtually smooth on the inner whorls, or attenuated to prominently penta-

CRETACEOUS FAUNAS FROM SOUTH AFRICA 261

Fig. 201. Submortoniceras condamyi (Collignon, 1948). SAS—Z1880. x 0,64.

tuberculate on the body chamber, as the following specimens will illustrate.

Specimens SAS-—76/1 (Fig. 205), SAS—Z1880 (Fig. 201), SAS—-Z1140, and SAS-—

A2084 have virtually smooth flanks on the inner whorls, save slight undulations

indicative of incipient ribbing. In SAS-76/1 (Fig. 205), and SAS-Z1880

(Figs 201-202) parts of the earliest whorls are preserved, showing that the

smooth stage is preceded by a more coarsely ornamented earlier stage. Slight

swellings (?constrictions) are noticeable on the inner whorls of SAS-Z1880

(Fig. 202) and SAS-Z76/1 (Fig. 205). Specimens SAM-PCZ5893 (Fig. 206),

262 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 202. Submortoniceras condamyi (Collignon, 1948). SAS-Z1880. Inner whorls. X 1.

(See also Fig. 201.)

CRETACEOUS FAUNAS FROM SOUTH AFRICA 263

Fig. 203. Submortoniceras condamyi (Collignon, 1948). SAM-—PCZ5892. Atypical specimen,

with wider umbilicus than normal and coarser ornament throughout, connecting with S. woodsi:

Xa: .

SAM-PCZ5894, and SAS-Z1952 have more prominent, though still weak,

ornament on the inner whorls when compared with the preceding specimens.

These specimens may be considered morphologically transitional to specimens

with coarse ornament on the inner whorls, such as SAM-—PCZ5717 (Fig. 207),

SAS-Z1756 (Fig. 208) and SAM-—PCZ5892 (Fig. 203).

All ornament, especially tuberculation, weakens progressively on the later

part of the phragmocone at various stages, but toward, and on, the body

264

ANNALS OF THE

SOUTH AFRICAN MUSEUM

Fig. 204. Submortoniceras condamyi (Collignon, 1948). NMB-D1191. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 265

chamber, ribbing becomes more prominent again. In some specimens, e.g.

SAS-Z1140 (Fig. 209) or SAS-A2084, distinct tuberculation develops on the

body chamber, which acquires a distinct Texanites-like appearance. Spacing

of ribbing on the body chamber, however, is variable. Specimens SAS—Z1756

(Fig. 208), SAS—76/1 (Fig. 205) and SAM-—PCP5717 (Fig. 207) lack lateral

tuberculation on the body chamber and may be regarded as being most Sub-

mortoniceras-like in this respect.

The venter is distinctly unicarinate throughout, except in SAS-Z1880

(Fig. 202) where the external (5) row of tubercles becomes elongated on the

inner whorls at a diameter of c. 80 mm, thus creating the appearance of two

lateral keels. On the body chamber of this specimen, however, the external (5)

tubercles are distinctly separate, and the venter unicarinate.

The suture is variable, ranging from wide, blocky saddles and lobes as in

SAS-Z1880 (Fig. 201), to long, narrow, thin-stemmed saddles and lobes as in

SAM-PCP5717 (Fig. 207).

Discussion

This species is here interpreted rather widely, but is characterized mainly

by the narrow umbilicus.

Collignon (1948) described a number of Submortoniceras species from

Berere, Madagascar, many of which appear comparable with, or identical to,

the present material. Matsumoto (1959: 130) and Howarth (1966: 63) have

already commented on the possible superfluity of some of the names applied

to the Madagascar material, and these views are further enhanced by Matsu-

moto’s description of the extremely variable Californian species S. chicoense as

discussed above.

As shown in Figure 210, many of the Madagascar species occur together

at the same restricted levels at Berere, whereas others have overlapping vertical

ranges, all suggesting that systematics can be greatly simplified.

The South African material is comparable with the following Madagascar

species, arranged in order of increasing umbilical width: S. angusteumbilicatum,

S. condamyi, S. spathi, S. renniei, S. punctatum, S. collignoni and S. tenuicostu-

latum. Collignon (1948: 96 et seq.) separated his species mainly on the basis

of details of whorl section, ornament and suture, but in view of the variation

encountered in S. chicoense and S. woodsi, it is doubtful if these differences

really warrant specific separation. Again, without having examined the material

in its exact stratigraphic context, the authors are reluctant definitely to synony-

mize any of Collignon’s species.

In terms of umbilical diameter, the South African material matches most

closely with S. condamyi, although distinction between the various species in

this respect is gradational (Fig. 211). Fortunately, Collignon (1932, 1948) pro-

vided ample illustrations of this species to illustrate the variation in ornament.

His illustrations show that ornament varies from virtually smooth flanks

(Collignon 1948, pl. 18(12) (fig. 2-2b)) through weakly and densely ornamented

266 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 205. Submortoniceras condamyi (Collignon, 1948). SAS-76/1. Specimen with smooth

inner whorls, but coarse ornament on body chamber. x 0,65.

on the inner whorls (Collignon 1932, pl. 5 (fig. 3a—b)) to coarsely ornamented

on the inner whorls (Collignon 1948, pl. 15). This variation in ornament com-

pares favourably with that encountered in the South African material. In terms

of ornament on the inner whorls, SAS—Z1756 (Fig. 208) and SAM—PCP5717

(Fig. 207) are comparable with Collignon’s 1948, pl. 15 specimen; SAM-—

PCP5893 (Fig. 206) with the holotype; and SAS—Z1180 (Figs 201-202) with

Collignon’s 1948, pl. 18(12) (fig. 2-2b) specimen.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 267

Fig. 206. Submortoniceras condamyi (Collignon, 1948). SAM-—PCZ5893. Specimen with

weak ornament on inner whorls. x 0,85.

The suture lines of the Zululand specimens are similar to those of the large

septate specimen figured by Collignon (1948, pl. 15) and of the holotype (Col-

lignon 1932: 37, fig. 20), although the elements in the former are generally

more ‘blocky’. The Pondoland specimens, SAM-—PCP5717 (Figs 207, 213A),

SAM-PCP 5883 (Fig. 212) and NMB-D1191 (Figs 204, 213B), have more incised

lobes and saddles and narrower elements. In accordance with the procedure

followed above, the species may be divided into two subspecies on the basis of

the suture line and more or less geographic restriction. The Zululand specimens

with blocky elements are to be referred to S. condamyi condamyi, whereas the

268 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 207. Submortoniceras condamyi (Collignon, 1948). Holotype of subsp. nov. umzambiense.

SAM-PCP5717. Specimen with strong ornament on inner whorls. x 0,62.

Pondoland specimens with narrower, more incised saddles and lobes are to be

referred to S. condamyi umzambiense ssp. nov. (holotype is SAM—PCP5717

(Fig. 207) from Bed A7 locality 1, Umzamba Cliff, at the Santonian/Campanian

boundary).

Development of tuberculation on the outer whorls, following the relatively

smooth phragmocone stage in some of the Zululand specimens, e.g. SAS-

CRETACEOUS FAUNAS FROM SOUTH AFRICA 269

A2084, Z1140 (Fig. 209), is comparable with the trend displayed by S. anguste-

umbilicatum Collignon; the whorl section in the latter species, however, seems

to be more compressed, although the narrow, finely splayed lateral lobe (L) is

comparable with S. condamyi umzambiense ssp. nov.

SAM-PCZ5893 (Fig. 206) has lateral ornament on the inner whorls very

similar to that of S. renniei (cf. Collignon 1948, pl. 17 (fig. 1)), but lacks the

very compressed whorl section ascribed to the species.

Fig. 208. Submortoniceras condamyi (Collignon, 1948). SAS-—Z1756. Specimen with coarse

ornament on inner whorls. x 0,57.

270 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 209. Submortoniceras condamyi (Collignon, 1948). SAS—Z1140. Specimen acquiring

stronger Texanites-like ornament towards and on body chamber. x 0,7.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 271

Species Level at Berere

1 Z 3 4 3 6 a 8 9

S. tenuicostulatum. . . x x x

S. dubium So canoe op x x —xX

SSHCOIMPNONE 5 x me x x

S.punctatum . . . : Xx x x xX —*xX

S. condamyi

iS. rarecostum .

S. piveteaui . : ; : x

S. pauper

S. elimatum

S. angusteumbilicatum .

aN SPATE ete) ote vn < x x

SMRCNNCL. celts eer Pts Xx

Fig. 210. Table illustrating stratigraphic distribution of Submortoniceras species at Berere,

Madagascar.

SAS-Z1952c is similar to S. punctatum (cf. Collignon 1948, pl. 18(12)

(fig. 1-la) in becoming stronger ornamented towards the outer whorls, but

does not have quite as strong ornament on the inner whorls.

S. spathi and S. collignoni have ornament comparable with this material,

but much more compressed whorl sections.

Differences between S. woodsi s.1. as here interpreted, and S. condamyi s.1.

are gradational. S. condamyi may be derived from S. woodsi s.l. through reduc-

tion of the umbilical diameter. Specimens SAM-—PCZ5883 (Fig. 212) and SAS-

A2084 may be regarded as being transitional between the two species in having

a smaller umbilical diameter, but retaining to a certain extent the Texanites-like

ornament.

Other Submortoniceras species described from Madagascar by Collignon,

e.g. S. dubium, S. rarecostum, S. piveteaui, S. debile, S. pauper, S. elimatum, and

S. rugetae, all have much coarser ornament than the species allied or compared

with S. condamyi. If differences in coarseness for forms « and y of S. chicoense

(see Matsumoto 1959, pl. 32, pl. 34 (fig. 1)) are taken into consideration, how-

ever, one is again confronted with the possibility that we may be dealing with

only one or a few very variable species.

Development of the pseudotricarinate venter at certain stages as in SAS-

Z1880 (Fig. 202) is reminiscent of S. mariscalense Young from the upper part

of the Lower Campanian of Texas. This latter species differs, however, in

losing all ornament on the outer whorls, barring the bisulcate venter. Unfortu-

D2 ANNALS OF THE SOUTH AFRICAN MUSEUM

200 A

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18 22 26 30

UMBILICAL WIDTH °/,——>

Fig. 211. Diagram to illustrate overlapping umbilical diameters of various Submortoniceras

species.

CRETACEOUS FAUNAS FROM SOUTH AFRICA DiS

nately, S. mariscalense is monotypic, thus precluding detailed comparison

between the two species.

Occurrence

Upper Santonian to Lower Campanian of Pondoland and Zululand, and

Lower Campanian of Madagascar.

Genus Bevahites Collignon, 1948

Type species

Bevahites bevahensis Collignon by original designation of Collignon (1948).

Diagnosis

Shell of variable size; generally small, with compressed or subsquare

whorls.

The pentatuberculate stage is attained rapidly. Adult ornament is charac-

terized by the proximity of the submarginal (3) and marginal (4) tubercles, and

multiplication of the external (5) tubercles. Due to bifurcations many more

external than internal rows of tubercle occur.

Discussion

Bevahites is poorly represented in the present collections which offer

little basis for discussion of the genus. Originally Parabevahites was included in

Bevahites as a subgenus, but most workers now follow Wright (1957: L432) in

referring Parabevahites to Paratexanites as a subgenus, and even consider

including Parabevahites in the synonomy of Paratexanites as is done here

(see p. 14).

Bevahites is normally easy to distinguish from the other texanitid genera

because of the proximity of the submarginal (3) and marginal (4) tubercles, and

also because of the multiplication of the external row of tubercles. In this latter

respect there is close comparison to Menabites s.s. Both have more external (5)

tubercles than umbilical (1) ones, but those of Bevahites are also partially due

to extensive bifurcations. It is difficult to distinguish between Bevahites species

which lack the pronounced doubling of the submarginal (3) and marginal (4)

tubercles, and species of Menabites s.s. which attain the pentatuberculate stage

of development at an early stage.

From the list supplied below, it is clear that Bevahites is virtually restricted

to Madagascar, with only two reports from the Gulf Coast of North America

and specifically unidentifiable material from France (Fabre-Taxy 1963: 19-20).

To this may now be added a new species and two doubtful contenders from the

South African Cretaceous.

Species referred to Bevahites in the literature are:

B. bevahensis Collignon (1948: 84, pl. 11(5) (fig. 3-3b)) from the Upper San-

tonian of Madagascar and Gulf Coast of North America, possibly ranging

up to the Lower Campanian (including Collignon’s ‘mutation’ intermedia).

274 ANNALS OF THE SOUTH AFRICAN MUSEUM

B. dichotomus Collignon (1948: 93, pl. 7(1) (fig. 4), pl. 17(11) (fig. 1-1b)) from

the Lower Campanian of Madagascar.

B. costatus Collignon (1948: 90, pl. 7(1) (fig. 5), pl. 15(9) (fig. 1-1b)) from the

Lower Campanian of Madagascar (including ‘mutations’ crassicostata

Collignon, 1948: 91, pl. 15Q) (fig. 2-2b) from the Lower Campanian of

Madagascar; costulata Collignon, 1948: 92, pl. 16(10) (fig. 22a) from the

Middle Campanian of Madagascar; rarecostata Collignon, 1948: 92,

pl. 16(10) (fig. 1) from the Middle Campanian of Madagascar; inornata

Fig. 212. Submortoniceras condamyi (Collignon, 1948). SAM-PCP5883. x 0,8.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 275

Fig. 213. Submortoniceras condamyi (Collignon, 1948). Suture lines of specimens referable to

subspecies umzambiense. A. PCP5715. B. NMB-D1191.

Collignon, 1948: 93, pl. 16(10) (fig. 3-3b) from the Middle Campanian

of Madagascar).

. costatus Collignon coahuilaensis Young (1963: 96, pl. 47 (figs 1-4), pl. 71

(fig. 5), text-fig. 34b) from the Lower Campanian of the Gulf Coast of

North America.

. curvicostatus Collignon (1948: 87, pl. 13(7) (fig. 1-1b)) from the Lower

Campanian of Madagascar.

. lapparenti Collignon (1948: 88, pl. 14(8) (fig. 1-1b)) from the Middle Cam-

panian of Madagascar.

. quadratus Collignon (1948: 86, pl. 12(6) (fig. 3-3b)) from the Lower and

Middle Campanian of Madagascar.

. romani Collignon (1948: 95, pl. 17(11) (fig. 2—2a)) from the Middle Cam-

panian of Madagascar.

. subbevahensis Collignon (1948: 85, pl. 11(5) (fig. 4-4a)) from the Upper

Santonian of Madagascar.

subogivalis Collignon (1948: 87, pl. 13(7) (fig. 2-2b)) from the Middle Cam-

panian of Madagascar.

subquadratus Collignon (1948: 89, pl. 13(7) (fig. 3—3a, pl. 14(8) (fig. 2—2a))

from the Lower and Middle Campanian of Madagascar.

Occurrence

Bevahites occurs mainly in Madagascar, from the Upper Santonian to

Middle Campanian and Upper Santonian of the North American Gulf Coast,

and imprecise horizons in the Santonian and Campanian of Zululand. Specifi-

cally unidentifiable material was reported from the Lower Santonian of France

(Fabre-Taxy 1963).

276 ANNALS OF THE SOUTH AFRICAN MUSEUM

Bevahites? enigma sp. nov.

Fig. 214

Holotype

SAS-H68/2 (Fig. 214), locality 103, hill slopes near the Nyalazi River

Estuary, Zululand, St Lucia Formation, Campanian I or II.

Etymology

Refers to uncertain generic allocation.

Material

The holotype only.

Dimensions

D Wb Wh Wb: Wh U Ur(1) LZt(2) St(3) Mrt(4) Et(5)

90,0 42,0(46,7) 37,0(41,1) 1,13 30,0(33,3) 19 ? 23 29 36

Description

The specimen is septate throughout, but lacks the very innermost whorls.

The inner whorls preserved have a prominently depressed whorl section, much

wider than high, but with increasing diameter the whorl section becomes more

rounded, with a slightly outward-leaning umbilical wall, a prominent umbilical

edge merging into little-inflated flanks which join imperceptibly with a broadly

rounded to flattened venter.

At a diameter of 35 mm, ornament consists of a rounded umbilical (1)

tubercle, a very prominent, radially elongated ventrolateral (submarginal)

tubercle, closely situated indistinct marginal (4) tubercles and prominently

rounded external (5) tubercles. The external (5), and in some cases already the

submarginal (4), tubercles outnumber the submarginal (3) ones due to bifurca-

tion or intercalation of ribbing near the venter at the site of the submarginal (3)

tubercle. With increasing diameter, the submarginal (3) tubercles become

weaker, and the distance between the latter and the marginal (4) tubercles

becomes greater. Lateral (2) tubercles start appearing at a diameter of c. 45 mm

on the dorsal quarter of the flanks as very indistinct little nodes.

With further increase in diameter, all tuberculation weakens and becomes

subordinate to ribbing, and becomes equidistantly spaced over the flanks in

the process.

The ratio of umbilical (1) to submarginal (3), marginal (4) and external (5)

tubercles varies tremendously due to bifurcations and intercalations, as illus-

trated diagrammatically in Figure 214D. Bifurcations or intercalations may

occur at the umbilical (1), the submarginal (3) or the marginal (4) tubercles,

giving rise to the odd ratio of tubercles as provided in the list of dimensions.

Thus, one umbilical (1) tubercle may correspond to up to four external (5)

tubercles.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 2TH

Fig. 214. Bevahites ? enigma sp. nov. Holotype SAS-H68/2. x 1.

278 ANNALS OF THE SOUTH AFRICAN MUSEUM

The keel is entire and rather prominent on the early parts of the phragmo-

cone, but tends to weaken on the last part preserved, and also shows slight

undulations.

The suture is imperfectly preserved, showing a wide, bifid lateral lobe (L).

Discussion

This species is readily recognized by the stout whorl section and by the

irregularly bifurcating and intercalating ribbing, so much so that it requires

specific rank, even though monotypic. The generic affinity of the species, how-

ever, is enigmatic, hence the name. The relative late persistence of a quadri-

tuberculate stage places this species close to Bevahites, whereas the eventual

equidistant pentatuberculate ornament is more in line with that of Menabites.

For the present it is considered advisable to refer the species to Bevahites with

a mark of interrogation, as it appears to fit best in the group of Bevahites sp. gr.

ex. quadratus of Collignon (1948: 86) which includes the nominate species

B. quadratus, B. costatus, B. subogivalis, and B. lapparenti. None of these

species, however, has as narrow an umbilical width or as irregularly dicho-

tomizing ornament. The closest ally amongst the former is probably B. lappa-

renti, which has a similar strongly developed ventrolateral tubercle in the early

stages and which later splits into two.

As far as irregular bifurcations and intercalations are concerned, analogies

are to be found in B. bidichotomus, but the latter has a much more compressed

whorl section than the Zululand species.

Bevahites sp. A gr. ex. B. subquadratus Collignon, 1948

Fig. 215

Material

NMB-D1185A and D1185B from an unknown locality in the Morrisvale

area, probably the authors’ (Kennedy & Klinger 1975) locality 147 of Santonian

Age.

Description

The two specimens differ considerably in terms of strength of ornament,

but are both characterized by a compressed whorl section with maximum

whorl breadth at the lateral tubercle.

NMB-D1185A (Fig. 215A) has smooth inner whorls up to a diameter of

c. 15 mm. At a diameter of c. 30 mm virtually complete Bevahites ornament is

present, though very weak, but the submarginal (3) tubercle appears absent at

that stage. With increasing diameter, however, the ornament becomes stronger,

especially the lateral (2) and external (5) tubercles.

NMB-D1185B (Fig. 215B-D), on the other hand, already has a distinct

lateral ornament at 15 mm diameter, consisting of an umbilical (1) tubercle,

279

CRETACEOUS FAUNAS FROM SOUTH AFRICA

Migs:

vinnie

yyy

, 1948. A. NMB-D1185A.

ignon

subquadratus Coll

NMB-D1185B.

gr. ex. B.

B-D.

Fig. 215. Bevahites sp

280 ANNALS OF THE SOUTH AFRICAN MUSEUM

connected by a stout rib to a prominent ventrolateral spine leaning against the

umbilical wall. At 30 mm diameter the total ornament is visible, showing the

typical joined submarginal (3) and marginal (4) tubercles and proliferation of

the external (5) tubercles. The lateral (2) tubercle has apparently just appeared

at this diameter, and is still weakly developed. Ornament strengthens with

increasing diameter, and at a diameter of 50 mm the submarginal (3) and

marginal (4) tubercles are completely separated. Ornament at this stage consists

of radially elongated umbilical (1), very strong lateral (2), weak clavate sub-

marginal (3) and marginal (4), and strong clavate external (5) tubercles.

Unfortunately the outer whorl of NMB-—D1185B is crushed and eroded,

but it shows the adult ornament consisting of strong umbilical, very strong

lateral, and very weak marginal and submarginal and, again, strongly clavate

external tubercles, and a very weak, narrow keel.

The suture is not exposed in either of the specimens.

Discussion

Due to lack of precise stratigraphic data, it is not known if we are here

dealing with one or two species, one with smooth inner whorls, and another

with coarser-ornamented inner whorls, a situation perhaps comparable with

that found in Texanites soutoni s.l. or Plesiotexanites stangeri. According to

the data in the late E. C. N. van Hoepen’s catalogue, the material was found

near the confluence of the Msinduzi and Mkuze Rivers, which is probably the

equivalent of, or close to, the authors’ (Kennedy & Klinger 1975) locality 147

which was tentatively dated as Santonian.

For the above reasons it is considered best to refer to the material merely

as Bevahites sp. A gr. ex. B. subquadratus, which includes the nominate species,

B. subquadratus, B. costatus (including mutants crassicosta, costulata, rarecosta

and inornata), B. bidichotomus and B. romani.

The inner whorls of B. subquadratus (see Collignon 1948, pl. 7(1) (fig. 5))

are similar to the coarsely ornamented inner whorls of NMB-D1185A (Fig.

215A), but ribbing is far more sinuous. Despite slight compression of the

Zululand specimens, the holotype of B. subquadratus (Collignon 1948, pl. 14(8)

(fig. 2-2a)) also appears more inflated.

B. costatus, including Collignon’s (1948) ‘mutations’ crassicostata, costulata,

rarecosta and inornata has a similar compressed whorl section, but in all cases

lacks the strong development of external tubercles, and rather tends to have a

more rounded venter.

B. romani is related to the Zululand material in the eventual separation

of the submarginal tubercles, but differs mainly in strength of the different rows

of tubercles and in the late development of the lateral tubercle.

Occurrence

Probable Santonian of Zululand.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 281

Bevahites sp. B. gr. ex. B. subquadratus Collignon, 1948

Fig. 216

Material

NMB-D1067 from an unknown locality near the north-western end of

False Bay, Zululand, probably at locality 74 towards the top of the section

measured by Kennedy & Klinger (1975: 293, text-fig. 8).

Description and discussion

The specimen consists of about a quarter of a whorl, is septate throughout

and very sparsely ornamented. The whorl section is much higher than wide,

with a vertical umbilical wall, slightly outward bulging flanks up to midflank,

and then converging to a narrow, flat venter with a prominent row of clavate

external (5) tubercles (Fig. 216B). Lateral ornament is very weak, consisting

mainly of radially elongated umbilical (1) tubercles and about twice as many

clavate external (5) tubercles. Lateral (2) tubercles merely appear as low nodes,

and submarginal (3) and marginal (4) tubercles are absent for all practical

purposes. The sutures are crowded, but appear to be very incised.

The whorl section is obviously that of the group of B. subquadratus, but

on the basis of this limited material positive identification is not really possible.

The whorl section is reminiscent of that of the B. costatus specimen figured by

Collignon (1948, pl. 15(9) (fig. 2a)), but has a more flattened venter and better

developed ventral tubercles.

This specimen differs from the previously described specimens of the

group B. subquadratus in having a more compressed whorl section, and also in

lacking the strong lateral ornament of the latter.

Occurrence

Locality data are imprecise, but probably Santonian to Lower Campanian.

Genus Menabites Collignon, 1948

Type species

Menabites menabensis Collignon, 1948, by original designation of

Collignon, 1948.

Diagnosis

Menabites is identified by the relatively long persistence of the tritubercu-

late stage, sometimes apparently to maturity, and also by the multiplication of

the tubercles of the external (5) row, numbering two to three times as many as

the marginal (4) ones.

Discussion

The whorl section, nature of ornamentation and persistence of the diag-

nostic trituberculate stage are very variable, so much so that, apart from

282 ANNALS OF THE SOUTH AFRICAN MUSEUM

Menabites s.s., three other subgenera are recognized: Bererella, Australiella

and Delawarella.

Menabites s.s. contains those forms in which the trituberculate stage passes

relatively rapidly into a final pentatuberculate texanitine stage.

Bererella (type species M. (B.) bererensis Collignon, 1948) contains widely

umbilicate, flat forms with few and widely-spaced ribs.

Australiella (type species M. (A.) australis (Besairie)) contains those forms

with wide whorl sections, sometimes strongly inflated and enormous lateral

(2, 3, 4) tubercles, and may apparently retain this trituberculate stage to large

diameters or throughout life.

Delawarella (type species M. (D.) delawarensis Collignon) contains forms

with numerous ribs, closely spaced, often flexuous, and with attenuated orna-

ment and a narrow umbilicus.

Of all the described species and subspecies of Menabites s.1., about half

appear to be restricted to Madagascar; the remaining known reports are from

the Gulf Coast and adjacent areas of North America, Zululand and Hokkaido.

As in Submortoniceras, it is difficult to decide whether this distribution pattern

reflects real geographically separated species groups in each area, or, rather,

the individual systematicist’s approach towards classification.

Menabites s.\. is very easy to distinguish from the majority of other texani-

tids on account of the multiplication of the external row of tubercles, but also

on stratigraphic grounds, being apparently the last texanitids to survive of a

very successful lineage dating from the Upper Coniacian.

Differentiation between the four subgenera as outlined above sometimes

becomes difficult, as characteristics often overlap, and the diagnostic differences

appear to be based on ontogenetic features.

Further differences arise in distinguishing between Menabites s.s. and

Bevahites, both of which have a multiplied external row of tubercles.

The basic distinguishing feature between Menabites s.s. and Bevahites is

the longer persistence of the trituberculate stage in the former, and, to a lesser

extent the proximity of the submarginal (3) and marginal (4) tubercles in

Beyahites, although application of this criterion sometimes becomes subjective

as the Zululand material shows.

Unless the inner whorls are preserved to reveal details of ontogeny, it is

difficult to distinguish between late representatives of Submortoniceras, e.g.

S. johannisludovici Collignon, and smooth forms of Menabites (Delawarella).

The Zululand specimens of Menabites are very large, with diameters of up

to 700 mm in one M. (Delawarella) species. This, combined with the general

lack of the early inner whorls, makes it difficult to identify these specimens with

the much smaller species described from Madagascar. Difficulties occur especi-

ally in the interpretation of M. (Australiella) species. Apart from the fact that all

the Zululand representatives of this subgenus are highly variable, they grow to

much larger diameters, and in doing so pass from the typically trituberculate

Australiella stage to a pentatuberculate Menabites or Bererella stage. Unfortu-

CRETACEOUS FAUNAS FROM SOUTH AFRICA 283

Fig. 216. Bevahites sp. B. gr. ex. B. subquadratus Collignon, 1948. NMB-D1067. x 1.

284 ANNALS OF THE SOUTH AFRICAN MUSEUM

nately, the authors have insufficient data on the Madagascan material to find

out whether these Australiella species were, in fact, all adult or immature.

Phylogenetic relationships between Menabites s.1. and the other texanitine

genera, and even between the subgenera within Menabites, are not quite clear.

In Madagascar, Menabites s.s. starts appearing in the upper part of the

Lower Campanian, Zone of Menabites boulei and Anapachydiscus arrialoorensis,

but is replaced by representatives of Australiella, Delawarella and Bererella

in the Middle Campanian. Data on the first appearance of Menabites in Zulu-

land are scant, but the abundant occurrence of Australiella and Delawarella

at the south-western tip of the Nibela Peninsula seems to suggest the same

temporal sequence.

This, however, is at variance with the views held by Matsumoto (1970: 298)

and Young (1963: 107). Their views are supported by the alleged occurrence of

Australiella in sediments of Santonian age. Locality data on Australiella austi-

nensis Young are confusing (Young 1963: 116), and Young considered it to be

‘probably Lower Santonian, but could be lowest Campanian’(!). Australiella

sp. aff. A. pattoni in Matsumoto (1970: 300) also lacks a firm dating and was

dated as ‘probably Santonian’ (Matsumoto 1970: 300).

On the basis of the Malagasy and Zululand material, the authors would

rather be inclined to derive Australiella, Delawarella and Bererella from

Menabites s.s.

The origin of Menabites s.l. is obscure, and the Zululand material provides

no direct information. Young (1963: 107) and Matsumoto (1970: 289) are

inclined to derive Menabites (or Australiella) from Protexanites. Protexanites

(Pleurotexanites) from the Mid-Santonian of Madagascar only has three rows

of tubercles, of which the external ones are multiplied as in Menabites s.1., and

is thus a possible ancestral form.

Another possibility, which closes the time gap between Mid-Santonian

and Early Campanian, is Bevahites. Through reduction of the lateral tubercle

and strengthening of the double ventrolateral tubercle, the initial trituberculate

situation as in early Menabites s.s. ontogeny can be derived.

Clearly, no satisfactory answer to this question will be found unless based

on detailed collecting.

Venzo’s (1936: 88, pl. 3 (fig. 12)) Mortoniceras vinassai is definitely not a

Menabites, but probably a Forresteria. The locality, ‘Riva sinistra del basso

Umsinene’ corresponds to the authors’ (Kennedy & Klinger 1975) locality 72

or 73 of Upper Coniacian or Lower Santonian age.

Species referred in literature to subgenus Menabites are:

M. (Menabites) belli Young (1963: 106, pl. 54 (fig. 1), pl. 58 (fig. 2), pl. 70

(figs 2-4, 7), text-fig. 15a) from the Lower Campanian of the Gulf Coast

of North America.

M. (Menabites) boulei Collignon (1948: 14, pl. 22 (fig. 1-1b)) from the Lower

and Middle Campanian of Madagascar.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 285

M. (Menabites) breistrofferi Collignon (1948: 19, pl. 24 (fig. 1-1b)) from the

Campanian of Madagascar.

M. (Menabites) cottreaui Collignon (1948: 16, pl. 23 (fig. 2-2b)) from the

Middle Campanian of Madagascar.

M. (Menabites) dabolavaensis Collignon (1948: 20, pl. 24 (fig. 3-3a)) from the

Lower and ?Middle Campanian of Madagascar.

M. (Menabites) densinodosus (Renz) (1936: 8, pl. 2 (fig. 1-1a)) from the Lower

Campanian of the Gulf Coast of North America.

M. (Menabites) gignouxi Collignon (1948: 15, pl. 22 (fig. 2-2b)) from the

Campanian of Madagascar.

M. (Menabites) internodosus (Renz) (1936: 10, pl. 3 (fig. 2—2b)) from the Lower

Campanian of the Gulf Coast of North America.

M. (Menabites) jacobi Collignon (1948: 13, pl. 20 (fig. 3-3b)) from the Middle

Campanian of Madagascar.

M. (Menabites) lenoblei Collignon (1948: 19, pl. 24 (fig. 1-1b)) from the Cam-

panian of Madagascar.

M. (Menabites) latissimus Collignon (1969: 192, pl. 594 (fig. 2244)) from the

Lower Campanian of Madagascar.

M. (Menabites) mazenoti Collignon (1948: 11, pl. 20 (fig. 2—2a)) from the Middle

Campanian of Madagascar.

M. (Menabites) menabensis Collignon (1948: 7, pl. 17 (figs 3a—b, 44a), pl. 18

(fig. 1-1b)) from the Lower Campanian of Madagascar.

M. (Menabites) menabensis var. lata Collignon (1948: 9, pl. 18 (fig. 2—2b)) from

the Lower Campanian of Madagascar.

M. (Menabites) multiformis Collignon (1948: 12, pl. 7 (fig. 8-8b), pl. 19

(fig. 1-la)) from the Middle Campanian of Madagascar.

M. (Menabites) paucituberculatus Collignon (1948: 21, pl. 24 (fig. 2—2a)) from

the Middle Campanian of Madagascar.

M. (Menabites) rarecostus Collignon (1969: 194, pl. 595 (fig. 2246)) from the

Lower Campanian of Madagascar.

M. (Menabites) savornini Collignon (1948: 9, pl. 7(1) (fig. 9-9a), pl. 19 (figs 2—2a,

3—3a), pl. 20 (fig. 1), pl. 21 (figs 1-1b, 2—2b)) from the Middle Campanian

of Madagascar.

M. (Menabites) tsirananai Collignon (1969: 196, pl. 595 (fig. 2247)) from the

Lower Campanian of Madagascar.

Menabites s.1. walnutensis Young (1963: 109, pl. 58 (figs 1, 4), text-figs 20ef, 26k)

from a loose block, presumably Lower Campanian of the Gulf Coast

region of North America.

Species referred to subgenus M. (Delawarella) in the literature are:

M. (Delawarella) bassae Collignon, 1948 (Basse 1931: 41, pl. 6 (figs 1-4); see

also Collignon 1948: 36, pl. 31 (fig. 3)) from the Middle Campanian of

Madagascar.

286 ANNALS OF THE SOUTH AFRICAN MUSEUM

M. (Delawarella) campaniensis (De Grossouvre) (1894: 84, pl. 13 (figs la—b,

3a—b)) from the Middle Campanian of France, and from the Lower Cam-

panian of the Gulf Coast of North America.

M. (Delawarella) danei Young (1963: 114, pl. 57 (fig. 6), pl. 62 (figs 1-2), pl. 64

(figs 1, 5), pl. 65 (figs 1-2), pl. 66 (figs 3-4), text-figs 24c, 33b) from the

Lower Campanian of the Gulf Coast of North America.

M. (Delawarella) delawarensis (Morton) (1830: 244, pl. 2 (fig. 4)) from the

Middle Campanian of Delaware, New Jersey and Texas.

M. (Delawarella) jeanneti Collignon (1948: 34, pl. 30 (fig. 3-3b), pl. 31 (fig. 1-1b))

from the Middle Campanian of Madagascar.

M. (Delawarella) jeanneti var. compressa Collignon (1948: 36, pl. 31 (fig. 2—2a))

from the Middle Campanian of Madagascar.

M. (Delawarella) roedereri Collignon (1948: 38, pl. 32 (fig. 1-1b)) from the

Middle Campanian of Madagascar.

M. (Delawarella) sabinalensis Young (1963: 112, pl. 54 (fig. 2), pl. 63 (figs 1,

3-4), text-figs 20c, 2le, 26c) from the Lower Campanian of the Gulf Coast

of North America.

M. (Delawarella) subdelawarensis Collignon (1948: 32, pl. 29 (figs la—b, 2a—b))

from the Middle Campanian of Madagascar.

M. (Delawarella) subdelawarensis var. lenticularis Collignon (1948: 43, pl. 30

(fig. 1-la)) from the Middle Campanian of Madagascar.

The following species have been referred to subgenus (or genus) Australiella

in the literature:

M. (Australiella) australis (Besairie) (1930: 638, pl. 64 (fig. 2—2a)) from the

Middle Campanian of Madagascar.

M. (Australiella) australis ingens Collignon (1970: 62, pl. 633 (fig. 2334)) from

the Middle Campanian of Madagascar.

M. (Australiella) antsirasiraensis Collignon (1948: 28, pl. 28 (fig. 3-3a)) from

the Middle Campanian of Madagascar.

M. (Australiella) austinensis Young (1963: 115, pl. 64 (figs 3-4), pl. 65 (fig. 6),

pl. 67 (figs 4-6), text-fig. 28e) from an imprecise horizon in the Gulf Coast,

reported as Senonian and ‘probably Lower Santonian, but could be lowest

Campanian’ (Young 1963: 116).

M. (Australiella) besairiei (Collignon) (1938: 75, pl. 4 (fig. 2—2b)) from the

Middle Campanian of Madagascar.

M. (Australiella) coronata Collignon (1970: 56, pl. 631 (fig. 2328)) from the

Middle Campanian of Madagascar.

M. (Australiella) moreti Collignon (1948: 28, pl. 28 (fig. 2-2b)) from the Middle

Campanian of Madagascar.

M. (Australiella) pattoni Young (1963: 116, pl. 65 (figs 4-5), pl. 66 (figs 1-2,

5-6), pl. 68 (figs 1-3, 6), text-figs 24b, 26h, 33ac, 34dg) from the Lower

Campanian of the Gulf Coast of North America, and, doubtfully, from an

unknown horizon, possibly Santonian, of Japan.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 287

M. (Australiella) souqueti Collignon (1970: 59, pl. 623 (fig. 2332)) from the

Middle Campanian of Madagascar. |

M. (Australiella) subaustralis Collignon (1948: 27, pl. 27 (fig. 3-3a)) from the

Middle Campanian of Madagascar.

M. (Australiella) tintanti Collignon (1970: 57, pl. 631 (fig. 2330)) from the

Middle Campanian of Madagascar.

M. (Australiella) welderi Young (1963: 117, pl. 65 (fig. 3), pl. 68 (figs 4-5, text-

fig. 25kn) from the Lower Campanian of the Gulf Coast of North America.

Species referred to subgenus Bererella in literature are:

M. (Bererella) aculeata Collignon (1948: 23, pl. 26 (fig. 2-2a)) from the Middle

Campanian of Madagascar.

M. (Bererella) atropsi Collignon (1969: 200, pl. 598 (fig. 2250)) from the Lower

Campanian of Madagascar.

M. (Bererella) bererensis Collignon (1948: 22, pl. 25 (fig. 1-1b)) from the Lower

Campanian of Madagascar.

M. (Bererella) bererensis mut. multicostata Collignon (1948: 198, pl. 27

fig. 1-1b)) from the Lower Campanian of Madagascar.

M. (Bererella) bererensis compressa Collignon (1969: 200, pl. 598 (fig. 2251))

from the Lower Campanian of Madagascar.

M. (Bererella) bifidata Collignon (1948: 25, pl. 26 (fig. 3)) from the Middle

Campanian of Madagascar.

M. (Bererella) rochi Collignon (1948: 25, pl. 27 (fig. 2—2b)) from the Middle

Campanian of Madagascar.

M. (Bererella) tenuis Collignon (1948: 24, pl. 25 (fig. 2-2b)) from the Middle

Campanian of Madagascar.

Occurrence

Menabites s.1. occurs profusely in the Lower and Middle Campanian of

Madagascar and Zululand, and in reduced numbers in the Gulf Coast and

adjacent regions of North America and also Hokkaido, where they allegedly

occur as early as Santonian. A single species is known from the Campanian of

France.

Menabites (Menabites) boulei Collignon, 1948

Fig. 217

Menabites boulei Collignon, 1948: pl. 22 (fig. 1-1b); 1969: 192, pl. 594 (fig. 2243).

Type

Holotype is the specimen figured by Collignon (1948, pl. 22 (fig. 1-1b)) by

original designation.

Material

SAM-PCZ5690, locality 100, north of Nkundusi, Zululand, St Lucia

Formation; originally considered to be Lower Santonian, but, on the basis of

this identification, now dated as Lower Campanian.

288 ANNALS OF THE SOUTH AFRICAN MUSEUM

— oo

Fig. 217. Menabites (Menabites) boulei Collignon, 1948.

SAM-PCZ5690. x 1.

Dimensions

D Wb Wh Wb: Wh U Int. Ext.

101,0 33,0(32,6) 39,0(38,6) 0,85 36,0(35,6) 11x2 18x2

Description

Unfortunately the innermost whorls are lacking, but parts of them and

their impressions indicate the presence of a large, ventrolateral Menabites node,

confirming the generic allocation.

The umbilical width is 35 per cent of the total diameter, and the dorsal

zone of impression very shallow, with whorl overlap scarcely to the marginal (4)

tubercle. The whorl section is basically compressed, higher than wide, with

slightly inflated flanks converging to a flattened venter.

Ornament in the species is very strong, consisting of conical, equally strong

umbilical (1) and lateral (2) tubercles, very strong conical to radially elongated

CRETACEOUS FAUNAS FROM SOUTH AFRICA 289

submarginal (3) tubercles, and very weak clavate marginal (4) and stronger

clavate external (5) tubercles.

Bifurcations or intercalations occur at the submarginal (3) tubercle, but

not regularly, as single ribs occur as well, resulting in a ratio of umbilical to

external tubercles of slightly less than 1 : 2.

The suture is poorly exposed, but features a large lateral lobe (L).

Discussion

This species is easily characterized by the strength of the ornament on the

outer whorl.

M. (M.) boulei and M. (M.) menabensis have similar inner whorls, but

differ on the outer whorls by the sparser ornament of M. (M.) boulei and also

the strength of the lateral (2) tubercle in the latter as compared to that in M. (M.)

menabensis. M.(M.) cottreaui has comparable ornament at similar stages, but has

a much more compressed whorl section as compared to M. (M.) boulei. M. (M.)

lenoblei has also been compared to the present species, and differs mainly in the

effacement of ornament on the later whorls, especially towards the venter.

Furthermore, the tubercles tend to be radially elongated. M. (M.) dabolavaensis

is close to M. (M.) boulei, but generally has less strong, but denser ribbing. In

addition, the ratio of external to internal tubercles in M. (M.) dabolavaensis is

greater, there being up to three times as many external than internal tubercles.

Occurrence

Menabites (M.) boulei is the index fossil for the uppermost Zone of the

Lower Campanian in Madagascar. Zone of M. boulei and Anapachydiscus

arrialoorensis, and thus allows for correct dating of locality 100 in Zululand

which the authors previously (Kennedy & Klinger 1975: 295) had erroneously

attributed to Lower Santonian.

Menabites s.1. sp. juv. indet.

Fig. 218B—C

Material

SAM-PCZ5921 from the south-western shores of False Bay north of

Nkundusi at locality 100, St Lucia Formation, Lower Campanian.

Description and discussion

A fragment of a septate whorl and the corroded impression of a small

Menabites may probably be referred to the subgenus Australiella. At a diameter

of 10 mm the umbilical (1), ventrolateral (2, 3, 4) and external (5) tubercles are

already prominently developed, and the keel appears entire. At 35 mm diameter,

ornament consists typically of small, pointed umbilical (1) tubercles, very large

nodose ventrolateral (2, 3, 4) tubercles and about two to three times as many

obliquely elongated clavate external (5) tubercles. The keel is well developed

and entire.

290 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 218. A. Menabites (Australiella) australis (Besairie, 1930). NMB—D1336B. B-C. Mena-

bites s.l. sp. juv. indet. SAM-PCZ5921. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 291

Specific identification of this fragment is impossible, but it is included to

show the early trituberculate ornament. Similar juvenile specimens have been

illustrated by Collignon (1948, pl. 7(1) (figs 8-9)) to illustrate the ontogenetic

development of Menabites.

Menabites (M.) boulei occurs at the same locality and the inner whorls

could possibly belong to that species.

Occurrence

Lower Campanian of Zululand.

Menabites (Australiella) australis (Besairie, 1930)

Figs 218A, 219-229, 230B, 231-240

Mortoniceras australe Besairie, 1930: 638, pl. 64 (fig. 2—2a).

Mortoniceras cf. australe Besairie, 1930: 638.

Menabites (Australiella) australis (Besairie): Collignon, 1948: 26, pl. 28 (fig. 1-1a).

Australiella australis (Besairie): Collignon, 1970: 54, pl. 630 (fig. 2326).

Type

Holotype is the specimen figured by Besairie (1930, pl. 64 (fig. 2—2a)) from

the Campanian of Menabe, Madagascar.

Material

SAM-PCZ5898, Bed 3 locality 110, on the Nibela Peninsula, Zululand,

St Lucia Formation, Campanian Il; BMNH-C81475, C81478, Bed 4 at the

same locality, Campanian III; SAM-—PCP5689, SAS-Z191, Z705, Z1847,

NMB-D1336A-D1336B, all from the same locality as SAM—PCZ5898 at

various unrecorded horizons at this section; BMNH-—C81476, C81482, C81485,

locality 109, on the Nibela Peninsula, St Lucia Formation, Campanian II.

Dimensions

D Wb Wh Wb: Wh U Int. Lt Ext.

PCZ5898 233,0 83,0(35,6) 83,0(35,6) 1,00 83,0(35,6) 20 20 34

D1336A 100,0 53,0(53,0) 34,0(34,0) 1,56 41,0(41,0) — 14 31

at 140,0 68,0(48,6) 50,0(35,7) 1,36 55,0(39,3) 20 17 35

at 182,0 81,0(44,5) 62,0(34,1) 1,31 71,0(39,0) 24 21 37

D1336B 86,0 48,0(55,8) 34,0(39,5) 1,41 —_ — 15 29

at 120,0 64,0(53,3) 52,0(43,3) 1,23 — — 16 31

at 147,0 78,0(53,1) 67,0(45,6) 1,16 51,0(34,7) — 17. 31

Z705 135,0 55,0(40,7) 46,0(34,1) 1,20 53,039,3) — — —

Z191 196,0 80,0(40,8) 65,0(33,2) 1,23 76,0(38,8) 22 21 39

After Collignon, 1948:

I 49 28(57) 22(45) 1,27 16(33) —_- —- —

II 62 43(70) 27(44) 1,59 22(35) —- —- —

III 90 54(60) 42(70) 1,28 34(38) —- —- —

IV (type) 92 56(61) 44(48) 1,27 35(38) —_- —- —

Description

This species, as here interpreted, may grow to a very large size; one speci-

men, SAM-PCZ5898 (Figs 219-220), is still septate at a diameter of 315 mm.

292 ANNALS OF THE SOUTH AFRICAN MUSEUM

S *

Fig. 219. Menabites (Australiella) australis (Besairie, 1930). SAM—PCZ5898. Largest known

specimen at 315 mm diameter, and still septate. Also shows transition from Australiella to

Menabites or Bererella adult stage. x 0,39.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 293

Fig. 220. Menabites (Australiella) australis (Besairie, 1930). SAM-PCZ5898. x 0,4.

(See also Fig. 219.)

294 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 221. Menabites (Australiella) australis (Besairie, 1930). NMB—D1336B.

x 1. Changes in whorl section during ontogeny. (See also Figs 222-229.)

CRETACEOUS FAUNAS FROM SOUTH AFRICA 295

Coiling is relatively loose with an umbilical width of the order of 35 to

40 per cent of the diameter. The whorl section and details of ornament change

continually through the ontogeny (Figs 221-229).

Unfortunately, none of the specimens has the very innermost whorls

preserved, but at a diameter of c. 80 mm, the whorl section is already distinctly

rectangular, much wider than high, with a very shallow dorsal zone of impres-

sion, little inflated, virtually parallel flanks and a slightly rounded venter

(Fig. 227). Ornament at this stage consists of small, conical umbilical tubercles,

connected in most cases by low, thick ribs to enormous bullate to spatulate

ventrolateral nodes, which in turn are connected by very indistinct riblets to

two or three rounded or obliquely elongated external tubercles. Some of the

umbilical tubercles appear intercalatory, not being associated with any ribs.

The keel is low and broad. Striking at these diameters are the enormous ventro-

lateral nodes and the curious, occasional intercalatory umbilical nodes.

With increasing diameter, the whorl section becomes more inflated, and

the ventrolateral nodes become smaller and narrower and eventually show

signs of division, giving rise to a new row of tubercles on the ventrolateral side.

During this process, the lateral and ventrolateral tubercles tend to become

absorbed in the ribs, which are now well defined. The diameter at which division

of the ventrolateral tubercle into two takes place is variable, ranging from

c. 120 mm in NMB—-D1336B to 150 mm in NMB-D1336A.

Last to form is the lateral tubercle (2), dorsolaterally of the original ventro-

lateral spine. By this time the whorl section is well rounded, though still wider

than high. With increasing diameter ribbing becomes bolder and tends to

absorb the tuberculation to some extent.

The available specimens are all phragmocones, the largest being 315 mm

in diameter. The suture has blocky saddles and lobes with minutely frilled

elements (Fig. 231B).

Discussion

The Zululand material is of extreme interest in showing virtually the whole

ontogenetic development, changing from prominently trituberculate through

quadrituberculate to pentatuberculate.

The authors are not entirely sure that their interpretation of the species is

wholly correct, due to great differences in size between the Madagascar and

Zululand specimens. It is not clear from Besairie’s (1930: 638) or Collignon’s

(1948 : 26-27, 1970: 54) descriptions of M. (A.) australis whether these specimens

are still septate, or adult. The Madagascar specimens, if adults, are all very

small, c. 80 mm—150 mm in diameter, when compared to the Zululand speci-

mens, which are still septate at diameters in excess of 300 mm. The inner whorls

of the Zululand specimens, with depressed, subrectangular whorl section and

enormous ventrolateral spines are, however, like typical Madagascar M. (A.)

australis. This raises the question of whether Madagascar M. (A.) australis

which are, in fact, trituberculate throughout, have arisen caenogenetically from

296 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 222. Menabites (Australiella) australis (Besairie, 1930). NMB-D1336B.

Stage preceding that of Figure 223. x 1.

a population similar to the much larger Zululand material, or whether this

species has been interpreted only in terms of incomplete material in Mada-

gascar. The holotype of M. (A.) australis, according to Besairie’s figures,

measures about 150 mm in diameter. None of the Zululand specimens is still

unequivocally trituberculate at that diameter, although specimens such as

NMB-D1336 (Fig. 229), with a very indistinct fourth row of tubercles, are

very close to the holotype. Besairie (1930: 638) had referred to the Zululand

material as Mortoniceras cf. australis, stating that it differed from M. australis

only by the possession of a doubled row of tubercles in lieu of a single row.

In view of the normal wide range of intraspecific variation in the Texani-

tinae, it is probably correct to refer the Zululand material to Besairie’s species,

and to regard the holotype of M. (A.) australis as an immature specimen.

Differences between M. (A.) australis and the majority of the other

M. (Australiella) species described from Madagascar, e.g. M. (A.) falloti,

M. (A.) besairiei, M. (A.) subaustralis, M. (A.) moreti, M. (A.) antsirasiraensis,

M. (A.) tintanti, and M. (A.) coronata are difficult to formulate, as they seem

CRETACEOUS FAUNAS FROM SOUTH AFRICA 297

to grade into each other both in a vertical and in a lateral sense. The majority

of these species occur at the same stratigraphic level in Madagascar, and differ

mainly in details of whorl section and appearance or attenuation of ornament.

In view of the normal wide range of intraspecific variation, the authors doubt

if all these names should be retained.

Australiella australis ingens was separated by Collignon (1970: 62) from

the nominate subspecies on the basis of the strong development of the ventro-

Fig. 223. Menabites (Australiella) australis (Besairie, 1930). NMB-—D1336B.

Stage following that of Figure 222, and preceding that of Figure 224. x 1.

298 ANNALS OF THE SOUTH AFRICAN MUSEUM

MSiltidts,

Fig. 224. Menabites (Australiella) australis (Besairie, 1930). NMB-D1336B.

Stage following that of Figure 223, and preceding that of Figure 225. x 0,9.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 299

Fig. 225. Menabites (Australiella) australis (Besairie, 1930). NMB-D1336B.

x 0,8.

300 ANNALS OF THE SOUTH AFRICAN MUSEUM

lateral spines, the rounding of the venter and attenuation of the keel and external

row of tubercles. None of the Zululand specimens shows this development and

no data can be added.

Relationships with the closely allied M. (A.) falloti described below (p. 315)

are not quite clear, but it seems that M. (A.) falloti grades upward in the

exposures into M. (A.) australis. M. (A.) falloti has a more rounded whorl

Fig. 226. Menabites (Australiella) australis (Besairie, 1930). NMB-D1336B. Lateral view

of completely assembled specimen shown in Figures 222-225. x 0,69.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 301

Fig. 227. Menabites (Australiella) australis (Besairie, 1930). NMB-D1336A. x 1.

(See also Figs 218A, 228-229.)

302 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 228. Menabites (Australiella) australis (Besairie, 1930).

NMB-D1336A. x 1.

303

CRETACEOUS FAUNAS FROM SOUTH AFRICA

, 1930).

rie

(Besa

x 0

NMB-D1336A

ites (Australiella) australis

Menab

Fig. 229.

304 ANNALS OF THE SOUTH AFRICAN MUSEUM

(oo)

Fig. 230. Menabites (Australiella) species. Whorl sections. A. M. (A.) falloti. B. M. (A)

australis, C. M. (A.) besairiei. D. M. (A.) moreti.

CRETACEOUS FAUNAS FROM SOUTH AFRICA

305

Fig. 231. Menabites (Australiella) australis (Besairie, 1930). SAS—Z1847. Showing whorl

section and partial suture. x 1.

306 ANNALS OF THE SOUTH AFRICAN MUSEUM

section (Fig. 230A) and is pentatuberculate at a smaller diameter than M. (A.)

australis. Single specimens each of M. (A.) falloti, M. (A.)-australis, and M. (D.)

delawarensis occur respectively in Beds 1, 2 and 3 at locality 110 (see Kennedy

& Klinger 1975, fig. 9), suggesting that M. (A.) australis could be derived

proterogenetically from M. (A.) falloti. Definite conclusions, however, must

await more detailed collecting.

M. (A.) tintanti is a related species which also progresses beyond the tri-

Fig. 232. Menabites (Australiella) australis (Besairie, 1930). SAS-Z191. Specimen approxi-

mating the limits of M. (A.) moreti in being weaker ornamented and more rounded. x 0,7.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 307

tuberculate stage to quadrituberculate, and eventually pentatuberculate, though

the lateral tubercle is weak. Dimensions of the holotype given below are virtually

identical to the Zululand specimen NMB-D1336B at the same diameter.

D Wb Wb Wb: Wh U

M. (A.) tintanti after Collignun .. 120 60(50) 47(39) 1,28 45(38)

M. (A.) australis NMB-D1336B . . 120 64(53) 52(43) 1,23 —

Fig. 233. Menabites (Australiella) australis (Besairie, 1930). SAS-Z191. Specimen approxi-

mating the limits of M. (A.) moreti in being weaker ornamented and with a more rounded

whorl section. xX 0,65.

308 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 234. Menabites (Australiella) australis (Besairie, 1930). SAS-Z705. Specimen close to

M. (A.) coronata due to depressed, coronate whorl section x 1. (See Fig. 235A.)

Unfortunately, the holotype of M. (A.) tintanti was figured in lateral view

only, but it seems to occupy a morphologically intermediate position between

M. (A.) falloti and M. (A.) australis, in a sequence leading from a pentatubercu-

late stage through quadrituberculate to eventually trituberculate at comparable

diameters. Given more material it would most probably be possible to include

M. (A.) tintanti in the synonymy of one of the two species.

M. (A.) subaustralis has the same ornament and whorl section as M. (A.)

australis at small diameters, but after 60 mm all ornament weakens, thus differing

from the latter species.

309

CRETACEOUS FAUNAS FROM SOUTH AFRICA

x 1. B. Menabites (Dela-

irie, 1930). SAS—Z705. Specimen close

ion.

coronate whorl sect

is (Morton, 1831) SAS—Z2100. x 0,72.

Fig. 235. A. Menabites (Australiella) australis (Besa

warella) delawarens

to M. (A.) coronata due to depressed

310 ANNALS OF THE SOUTH AFRICAN MUSEUM

M. (A.) besairiei also seems somewhat transitional between M. (4.) falloti

and M. (A.) australis, but has a distinct octagonal whorl section (Fig. 230C)

compared to the rounded section of M. (A.) falloti or the rectangular depressed

section of M. (A.) australis. Transitional forms such as SAM—PCZ5689 (Figs

239-240) and SAM-PCZ5685 (Fig. 241) connect the species.

M. (A.) moreti has inner whorls very much like M. (A.) australis, but has a

Fig. 236. Menabites (Australiella) australis (Besairie, 1930). SAS-Z1847. x 0,8.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 311

Fig. 237. Menabites (Australiella) australis (Besairie, 1930). SAS—Z2101. x 0,84.

more rounded, narrower whorl section (Fig. 230D) than the latter, and has

differently evolving ornament in that the ventrolateral spine weakens and

becomes absorbed in the ribbing. SAS—Z191 (Fig. 232) is very much like

M. (A.) moreti, in being more inflated and weaker ornamented than typical

M. (A.) australis, pointing to the close relationship between the two species.

M. (A.) antsirasiraensis lacks the depressed whorl section and loses the

ventrolateral spine at diameters between 70 and 80 mm.

312 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 238. Menabites (Australiella) australis (Besairie, 1930). SAS-Z2102. x 0,9.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 313

M. (A.) coronata has a whorl section (Collignon 1970, pl. 631 (fig. 2328))

comparable to typical M. (A.) australis though not quite as depressed

rectangular. Here the ventrolateral spines are not as strong and spatulate

and about four external tubercles occur per spine. The whorl section of SAS-

Z705 (Figs 234-235A) is virtually identical to that of the holotype of M. (A.)

coronata, but it lacks the proliferation of external tubercles.

Fig. 239. Menabites (Australiella) australis (Besairie, 1930). SAM-PCZ5689. Transitional

to M. (A.) besairiei. x 0,6.

314 ANNALS OF THE SOUTH AFRICAN MUSEUM

g Yi

“py ,

Fig. 240. Menabites (Australiella) australis (Besairie, 1930). SAM-

PCZ5689. With whorl section transitional to M. (A.) besairiei.

x 0,8.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 315

M. (A.) austinensis was regarded as being close to M. (A.) australis by

Young (1963), but was said to differ on account of having weaker ventrolateral

clavae and stronger umbilical tubercles. These differences could all probably be

incorporated in the intraspecific variation of M. (A.) australis as here interpreted,

but the stratigraphic position of the species is perplexing. The species is based

on two specimens, both with dubious locality data. Young (1963: 116), how-

ever, concludes that the species is either from ‘Formation B or the Desau

Chalk. Formation B seems the most likely. . . .” This would place the species in

either Lower Santonian or Lower Campanian, probably Lower Santonian,

and would be the oldest record of the subgenus. Until the question on the

exact stratigraphic position is resolved, it is considered advisable to maintain

the species apart from M. (A.) australis.

M. (A.) pattoni differs from M. (A.) australis in lacking the depressed

whorl section in the early stages.

Retention of the trituberculate stage to a great diameter, and the presence

of occasional intercalatory umbilical tubercles in M. (A.) australis, is very

reminiscent of the situation as found in Plesiotexanites matsumotoi sp. nov. from

the Middle Santonian of the Umzamba Formation. Apart from a more evolute

mode of coiling in the latter, it also lacks the proliferation of external tubercles

characteristic of Menabites. This seems to be just another example of hetero-

chronous partial convergence with little genetic relationship.

Occurrence

Middle Campanian, Zone of Delawarella subdelawarensis and Australiella

australis in Madagascar, and Campanian II-III of Zululand.

Menabites (Australiella) falloti (Collignon, 1932)

Figs 230A, 241-243

Mortoniceras falloti Collignon, 1932: 37, pl. 5 (fig. 1-1b); 1938: 76.

Type

The holotype is the specimen figured by Collignon (1932; pl. 5 (fig. 1-1b))

from the Senonian of Zululand, collected by P. Fallot in 1929 and presently

housed in the Palaeontology Collections of the Geological Institute, Nancy.

Material

SAM-PCZ5870, Bed 1 locality 110, foreshore exposures at the south-

western tip of Nibela, Zululand, St Lucia Formation, Campanian II; SAS-

Z843, Z1547, Z2097, all from an unknown horizon at locality 109 or 110 at

the south-western tip of the Nibela Peninsula, St Lucia Formation, Cam-

panian II; BMNH-C81443-C81444, C81477, locality 109, St Lucia Formation,

Campanian II.

316 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 241. Menabites (Australiella) falloti (Collignon, 1932). SAM-

PCZ5685. With whorl section transitional to M. (A.) besairiei.

xan:

CRETACEOUS FAUNAS FROM SOUTH AFRICA 317

Dimensions

D Wb Wh Wb: Wh U Int. L. Ext.

Holotype after

Collignon 90 34 (37,8) 35,0(38,9) 0,97 30,0(33,3) 22

118,0 46,0(38,9) 47,0(39,8) 0,98 35,0(29,6) 14—-— —

Z843 124,0 54,0(43,5) 45,0(36,3) 1,20 — —

Z2097 176,0 63,0(35,8) 61,0(34,7) 1,03 58,0(32,9)

Description

Coiling is moderately involute with an umbilical width of the order of

30 to 33 per cent of the total diameter. Whorl overlap is up to the fourth row

of tubercles and the dorsal zone of impression is very shallow.

The whorl section is rounded, as wide as high in the early stages of growth

(Fig. 243) but later becomes higher than wide (Fig. 230A); in some cases

extremely so.

None of the Zululand specimens has the innermost whorls preserved, but

at a diameter of c. 70 mm all five rows of tubercles are already present. These

are: a conical umbilical (1) tubercle connected to a thickened rib which con-

tains the second, third and fourth rows of tubercles, and of which the third

row is most prominent. At the fourth row faint bifurcations become noticeable,

ending in spirally elongated external (5) tubercles which protrude far beyond

the venter on either side of a broad, weak central keel. In some cases it appears

as if the bifurcations already originate at the third tubercle.

Ornament generally becomes stronger towards the later part of the phrag-

mocone, but weakens again towards the body chamber.

The suture has broad saddles and lobes with minutely frilled terminations.

Discussion

This species is distinguished by the more or less rounded whorl section in

the early stages of growth and by the early appearance of the pentatuberculate

stage. Differences between M. (A.) falloti and M. (A.) australis, and even

M. (Delawarella) delawarensis are gradational, as discussed above.

Subgeneric identity of the species is subjective. It may be argued that

because of the relative early appearance of the pentatuberculate stage it should

be referred to Menabites s.s. Because of the close resemblance to the holo-

type of the subgenus M. (Australiella), however, it is here considered advisable

to refer the species to subgenus Australiella rather than Menabites s.s. It

may be noted here that Collignon also appeared to be in some doubt

as to the subgeneric allocation in his 1948 monographic description of the

Texanitinae. In comparing the species with M. (A.) australis (Collignon 1948:

27) he 1eferred to it as Menabites (Australiella) falloti, but in his species list of

the Texanitinae in the same volume (Collignon 1948: 44) refers it to Bererella.

Specimen SAS—Z843 (Figs 242-243) is closest to the holotype, which was

most probably collected at the same locality by P. Fallot in 1929, during the

Zululand excursion of the XV Session of the International Geological Congress.

318 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 242. Menabites (Australiella) falloti (Collignon, 1932). SAS-Z843. x 1.

Differences between M. (A.) falloti and M. (A.) australis, described above,

are to be found mainly in the longer retention of the trituberculate stage and

in the depressed rectangular whorl section of the latter species in the early

Stages.

Although sufficient precise stratigraphic data are not available, it appears

possible to derive M. (A.) australis from M. (A.) falloti caenogenetically as

discussed above.

Specimen SAM-—PCZ5870 differs from the rest of the material in being

much larger and in having a much more compressed section on the inner whorls,

though the latter may be partially due to secondary crushing. Ornament on

this specimen also weakens on the outer whorls, and may possibly connect

CRETACEOUS FAUNAS FROM SOUTH AFRICA 319

Fig. 243. Menabites (Australiella) falloti (Collignon, 1932). SAS-Z843. x 1.

320 ANNALS OF THE SOUTH AFRICAN MUSEUM

with M. (Delawarella) gigas sp. nov., described below.

SAM-PCZ5685 (Fig. 241) has inner whorls typical of M. (A.) falloti, but

at a diameter of c. 180 mm, has an octagonal whorl section, very similar to that

of M. (A.) besairiei. It is easily distinguished from the latter, however, on

account of the early appearance of the pentatuberculate stage.

M. (A.) tintanti is a similar, large species, and was compared to M. (A.)

falloti by Collignon (1970: 58); it differs mainly in retaining a quadrituberculate

stage to a large diameter. SAS—Z2097 appears transitional to M. (A.) tintanti

in having a very weakly developed lateral tubercle throughout and robust

ribbing on the outer whorl. As discussed earlier, M. (A.) tintanti is intermediate

between M. (A.) falloti and M. (A.) australis, and, given more material, may

probably be synonymized with either of the two species.

The inner whorls of M. (A.) falloti resemble those of M. (Delawarella)

delawarensis, which occurs at approximately the same stratigraphic level, and

they may possibly be derived from a common ancestor. In larger specimens,

however, M. (Delawarella) delawarensis is easily distinguished by the loss of

lateral ornament.

Occurrence

Middle Campanian of Zululand and Madagascar, though apparently rare

in Madagascar.

Menabites (Delawarella) delawarensis (Morton, 1830)

Figs 244-247A

Ammonites delawarensis Morton, 1830: 244, pl. 2 (fig. 4); 1834: 37, pl. 2 (fig. 5). Whitfield,

1892: 252, pl. 42 (figs 6-8).

Mortoniceras delawarensis (Morton): Weller, 1907: 837, pl. 103 (fig. 1). Grabau & Shimer,

1910: 227, fig. 1508.

Menabites (Delawarella) delawarensis (Morton): Collignon, 1948: 29. Reeside 1962: 131,

pl. 72 (figs 1-3), pl. 73 (figs 1-5), pl. 74 (fig. 2).

Delawarella delawarensis (Morton): Young, 1963: 111, pl. 55 (fig. 5), pl. 61 (figs 1-6), pl. 63

(fig. 2), text-figs 15e, 20d, 25b, 26bfg, 27c, 29f.

Type

Holotype is the specimen figured by Morton (1830, pl. 2 (fig. 4)), housed

in the Philadelphia Academy of Sciences.

Material

SAM-PCZ5905, Bed 3 locality 110, south-western tip of the Nibela

Peninsula, Zululand, St Lucia Formation, Campanian II; SAS—Z2097-Z2098,

both from the same locality as above, but of unknown horizon. BMNH-C81438-

C81439, locality 109, St Lucia Formation, Campanian II.

Dimensions

D Wb Wh Wb: Wh U Int. L. Ext.

Z2098 145,0 60,0(41,4) 60,0(41,4) 1,0 44,0(30,3) 18 18 34

Z2097 70,0 31,0(44,3) 30,0(42,8) 1,03 24,034.22) — — —

CRETACEOUS FAUNAS FROM SOUTH AFRICA 321

Description

The material is not very well preserved, lacking the inner whorls, and

finer details of ornament are obscured by crystalline matrix.

Coiling is moderately evolute, the umbilicus comprising 30 to 40 per cent

of the diameter. The whorl section in all three specimens is virtually equi-

dimensional hexagonal, with a near-vertical umbilical wall, flat flanks parallel

up to the ventrolateral nodes on the inner whorls and then converging to a

flattened venter (Fig. 247A).

Fig. 244. Menabites (Delawarella) delawarensis (Morton, 1830). SAS-Z2098. x 1.

322 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 245. Menabites (Delawarella) delawarensis (Morton, 1830). SAS-Z2098. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 323

On the inner whorls, ribs are feebly prorsiradiate up to the middle of the

flanks where they pass through a large node, and then generally bifurcate

and continue weakly up to the clavate external (5) nodes. At a diameter of

c. 30 mm the ventrolateral node starts dividing into two on the ventral side,

giving rise to a smaller clavate marginal (4) row of tubercles. The lateral (2)

tubercles appear later, at c. 40 mm diameter, but these latter never really

become prominent.

On the largest specimen, SAS—Z2098 (Fig. 244), the five rows of tubercles

are spread out evenly over the flanks, and the submarginal (3) row is the most

prominent, being distinctly pointed. Towards the larger end of this specimen

tuberculation on the flanks weakens, and ribbing becomes dominant. The

external tubercles, however, become stronger with increasing diameter and

stand out as prominent serrate ridges. The keel, at this stage, shows low undula-

tions corresponding in number to the external tubercles.

The suture is not well exposed in either of the specimens.

Discussion

This species was discussed extensively by Reeside (1962) and Young (1963)

and not much can be added to their comments.

The species is easily recognized by the very strong ornament when com-

pared to other species of /. (Delawarella), and may in this respect be considered

A B C

Fig. 246. Menabites (Delawarella) delawarensis (Morton, 1830). SAS-Z2097. x 1.

324 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 247. A. Menabites (Delawarella) delawarensis (Morton, 1830). A. Whorl section of

SAS-Z2907. x 2. B. Menabites (Delawarella) subdelawarensis Collignon, 1948. Suture line

of SAS-Z2100. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 325

transitional between Menabites s.s. and M. (Delawarella).

M. (Delawarella) roedereri is similar in this respect in having strong orna-

ment, but differs mainly in having a more compressed whorl section.

Collignon (1948: 32) separated M. (Delawarella) subdelawarensis (described

below) as a Malagasy representative of this American species, differing mainly

in having weaker ornament, and also a more compressed whorl section. These

reasons appear sufficient for separation of the two species.

Unfortunately, none of the Zululand specimens has the body chamber

preserved, but the magnificent specimen illustrated by Reeside (1962, pl. 74

(fig. 2)) shows the low, broad ribbing on the flanks.

Occurrence

Campanian of Zululand, Gulf Coast region, and Delaware and New Jersey

regions of North America.

Menabites (Delawarella) subdelawarensis Collignon, 1948

Figs 247B-251

Menabites (Delawarella) subdelawarensis Collignon, 1948: 32, pl. 29 (figs 1-2).

Menabites (Delawarella) subdelawarensis var. lenticularis Collignon, 1948: 34, pl. 30 (fig. 1).

Delawarella subdelawarensis Collignon, 1970: 64, pl. 634 (fig. 2335).

Type

Holotype is Collignon’s (1948, pl. 29 (fig. 2)) specimen by original

designation.

Material

SAM-PCZ5901, Bed 3 locality 110, south-western tip of the Nibela Penin-

sula, Zululand, St Lucia Formation, Campanian III; SAS—Z2100 from an

unknown horizon at the same locality; BMNH-—C81443-C81444, locality 109,

St Lucia Formation, Campanian II.

Dimensions

D Wh Wb Wb: Wh U Int. L. Ext.

Z2100 221,0 84,0(38,0) 103,0(46,6) 0,81 59,0(26,7) 23 — —

PCZ5901 340,0 119,0(35,0) 155,0(45,6) 0,76 .110,032,4) — — 42

Description

Unfortunately, the specimens are in a poor state of preservation, but

partially permit examination of specific characteristics.

_ The umbilical width of the very large specimen, SAM-—PCZ5901 (Figs

248-250), which is still septate at the larger end, is probably a little too large

due to fracture of the last part of the whorl. An umbilical width of 26 per cent

as in the smaller specimen seems more realistic. The whorl section is massive

326 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 248. Menabites (Delawarella) subdelawarensis Collignon, 1948. SAM-—PCZ5901. Gigantic

specimen still fully septate. x 0,34.

throughout, higher than wide, with a dorsal zone of impression which embraces

preceding whorls up to the lateral tubercle, and a vertical to inward or outward

sloping umbilical wall merging abruptly with the flanks, which remain parallel

up to the lateral tubercle at about midflank, and then converge obliquely to a

very broad venter.

In SAS-—Z2100 (Fig. 251) the typical Menabites trituberculate ornament

is still visible at a diameter of about 40 mm, but thereafter very quickly becomes

pentatuberculate and rather weak. Ornament after that consists of relatively

weak ribs bifurcating occasionally at the umbilical edge, each bearing five

CRETACEOUS FAUNAS FROM SOUTH AFRICA 327

Fig. 249. Menabites (Delawarella) subdelawarensis Collignon, 1948. SAM—PCZ5901. Gigantic

specimen still fully septate. Opposite lateral view of Fig. 248. x 0,34. .

rows of tubercles of which the umbilical (1) and external (5) ones are strongest.

The lateral (2) tubercles are very weak, and the submarginal (3) and marginal (4)

ones only slightly stronger. All five rows of tubercles are spaced equidistantly

over the flanks.

In this smaller specimen, SAS—Z2100 (Fig. 251), ribs become bolder and

more widely spaced at the largest diameter, whilst the whorl section also appears

to become more inflated. In the larger specimen, SAM-—PCZ5901 (Figs 248-250),

all ornament weakens at the largest diameter with no distinct strengthening of

the ribs.

328 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 250. Menabites (Delawarella) subdelawarensis Collignon, 1948. SAM-—PCZ5901. Gigantic

specimen still fully septate. x 0,46. (See also Figs 248-249.)

CRETACEOUS FAUNAS FROM SOUTH AFRICA 329

Fig. 251. Menabites (Delawarella) subdelawarensis Collignon, 1948. SAS-Z2100. x 0,63.

The keel throughout is broad and low, and eventually becomes very

indistinct at large diameters.

The suture line is blocky with minutely frilled terminations, though details

are somewhat obscured by weathering and calcitic encrustation (Fig. 247B).

The lateral lobe (L) in SAS—Z2100 is wide and asymmetrically trifid, and deeper

than the external lobe.

330 ANNALS OF THE SOUTH AFRICAN MUSEUM

Discussion

Comparison of the Zululand material with that described from Mada-

gascar by Collignon (1948, 1970) is difficult due to great differences in size, the

largest described specimen from Madagascar (Collignon 1970: 68) being only

166 mm in diameter compared to the smallest Zululand specimen at 221 mm

diameter. Nevertheless, the massive whorls, and generally coarse ornament of

the Zululand specimens compare well with the Madagascar material.

The closest ally to M. (D.) subdelawarensis is undoubtedly M. (D.) jeanneti,

which also occurs in two forms; a normally inflated form and a compressed

form. Major differences between the two species according to Collignon (1948:

36) are that the whorls of M. (D.) jeanneti are less massive, the ribs straighter,

finer and denser, and the lateral lobe (L) is bifid instead of trifid.

The Zululand material seems to suggest that M. (D.) jeanneti could possibly

be derived from M. (D.) subdelawarensis through tighter coiling and prolifera-

tion of ribbing, but unfortunately insufficient material is as yet available to

fully substantiate this assumption.

The inner whorls of the larger specimen, SAM—PCZ5901 (Figs 248-250),

are remarkably like those of M. (D.) gigas sp. nov. which occurs at a slightly

lower stratigraphic level at the Nibela Peninsula, but in the latter increase in

whorl size is much more rapid.

Occurrence

Campanian III of Zululand, and the Mid-Campanian Zone of Delawarella

subdelawarensis and Australiella australis of Madagascar.

Menabites (Delawarella) sp. aff. jeanneti s.1. Collignon, 1948

Figs 252-255

Compare:

Menabites (Delawarella) jeanneti Collignon, 1948: 34, pl. 30 (fig. 3-3b) pl. 31

(fig. 1-1b).

Menabites (Delawarella) jeanneti var. compressa Collignon, 1948: 36, pl. 31

(fig. 2—2a).

Delawarella jeanneti Collignon: Collignon, 1970: 64, pl. 634 (fig. 2336).

Dimensions

D Wb Wh Wb: Wh U Int. L. Ext.

PCZ5691 143,0 56,0(39,2) 68,0(47,6) 0,82 36,0(25,2) 23 ——

Material

SAM-PCZ5691, Bed 7 locality 110, south-western tip of the Nibela Penin-

sula, Zululand, St Lucia Formation, Campanian III; and SAM-FB from the

collection of S. H. Haughton from an unknown horizon and locality in the

False Bay region of Zululand, but probably the same locality as above.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 331

Fig. 252. Menabites (Delawarella) sp. aff. jeanneti s.1. Collignon, 1948. SAM-—PCZ5691.

x 0,78.

Description

Coiling is involute with an umbilical diameter of about 25 per cent. The

whorl section is compressed with a prominent dorsal zone of impression, a

vertical to overhanging umbilical wall with a well-defined umbilical edge and

weakly inflated flanks with maximum width at the site of the lateral tubercle.

None of the specimens has the innermost whorls preserved, but at a

diameter of 45 mm ornament is already very much weakened with barely per-

ceptible lateral and submarginal tubercles. The umbilical tubercles are radially

332 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 253. Menabites (Delawarella) sp. aff. jeanneti s.1. Collignon, 1948. SAM-—-PCZ5691.

x 0,85.

CRETACEOUS FAUNAS FROM SOUTH AFRICA : 333

elongated and point strongly inward. With increasing diameter ribbing remains

weak and prorsiradiate with barely perceptible lateral (2) and submarginal (3),

and slightly stronger marginal (4), but progressively stronger umbilical (1) and

external (5) tubercles. Numerous intercalations and bifurcations occur, generally

at the site of the submarginal tubercle, but also occasionally at the umbilical

tubercle. This results in there being about twice as many external as internal

tubercles.

Specimen SAM-PCZ5691 (Figs 252-253) has part of the early body

chamber preserved. Here tuberculation weakens even more, and the ribs

become wider spaced.

The suture is only partially exposed in the present material. The keel, as

far as can be seen, is never very prominent.

Fig. 254. Menabites (Delawarella) sp. aff. jeanneti s.1. Collignon, 1948. SAM-FB. x 1.

334 ANNALS OF THE SOUTH AFRICAN MUSEUM

Discussion

This species is identified by the fine, dense ribbing throughout, and the

very poor development of the lateral and submarginal tubercles.

Collignon (1948: 34-36), in erecting M. (D.) jeanneti, distinguished between

a typical form and a more compressed form, var. compressa, the difference in

whorl breadth between the two forms being approximately 5 per cent. The

larger Zululand specimen, SAM-PCZ5691 (Figs 252-253), with a whorl breadth

of 39 per cent of the diameter, appears closer to the typical form of M. (D.)

jeanneti than to the compressed variety. The main difference between the Zulu-

land material and the Malagasy specimens of M. (D.) jeanneti, lies in the fact

that, in the adult stage, the latter lose ornament on the venter and take on the

appearance of a pachydiscid. In the Zululand specimens the venter remains

Fig. 255. Menabites (Delawarella) sp. aff. jeanneti s.1. Collignon, 1948. SAM-FB. x 1.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 335

more or less flat, and the external tubercles are prominent, hence it is advisable

to refer to the material as M. (D.) sp. aff. jeanneti rather than a definite reference.

The specimen described below as M. (Delawarella) sp. indet. has similar

weak ornament on the flanks, but lacks the strong development of the umbilical

and external tubercles, and, in addition, has a distinct crenulate keel.

M. (Delawarella) nibelae sp. nov. (discussed below) differs from the present

species in being slightly more narrowly umbilicate and in having a more inflated

whorl section.

The closest ally to the present species is M. (D.) subdelawarensis, from

which it is possibly derived through slight reduction of umbilical width, com-

pression of the whorls and fining of ornament.

Other species of M. (Delawarella) such as M. (D.) gigas sp. nov. and

M. (D.) delawarensis, all differ on account of the much more prominent

ornament.

Occurrence

Campanian of Zululand; in the Mid-Campanian Zone of Delawarella

subdelawarensis and Australiella australis of Madagascar.

Menabites (Delawarella) gigas sp. nov.

Figs 256-258

Holotype

SAM-PCZ5900 (Fig. 256), Bed 1 locality 110, south-western tip of the

Nibela Peninsula, Zululand, St Lucia Formation, Campanian II.

Etymology

Pertaining to great size.

Material

SAS-Z1951 and SAS-A1867, both from the same locality as the holotype

but from an unknown horizon, can also be referred to this species.

Dimensions

D Wb Wh Wb: Wh U

PCZ5900 c.700 — c.270(37) — c.240(34)

Description

Unfortunately none of the specimens has the very innermost trituberculate

whorls preserved. Coiling is involute, with a very rapid increase in whorl size,

and an umbilical width of the order of 30 to 35 per cent of the total diameter.

The whorl section throughout is higher than wide, but is more inflated on the

phragmocone than on the body chamber. The umbilical wall is vertical to

overhanging.

Ornament on the phragmocone is basically of the Menabites type, very

336 ANNALS OF THE SOUTH AFRICAN MUSEUM

0 100

Fig. 256. Menabites (Delawarella) gigas sp. nov. Holotype SAM-—PCZ5900. x 0,23.

Scale bar in millimetres.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 337

reminiscent of M. (Australiella) falloti (see p. 315), which occurs at the same

stratigraphic level. Ornament here consists of low, single ribs, each bearing a

distinct umbilical (1) tubercle, but low, rounded and indistinct lateral (2),

submarginal (3), and marginal (4) tubercles.

The body chamber, which is partially preserved on the holotype (Fig. 256)

and SAS-Z1951 (Fig. 257), is enormous, comprising at least half a whorl. All

lateral ornament is here effaced, and on the holotype this even affects the

umbilical tubercles.

The suture is imperfectly known, but includes a very wide, asymmetric

bifid lobe (L) (Fig. 258).

Fig. 257. Menabites (Delawarella) gigas sp. nov. Paratype SAS-Z1951. x 0,45.

338 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 258. Menabites (Delawarella) gigas sp. nov. Paratype SAS-

Z1951. Showing partial suture. x 0,95.

Discussion

This species is very easily recognized by virtue of its large size, lateral

compression and complete lack of ornament on the body chamber.

The inner phragmocone whorls are very similar to those of M. (Australiella)

falloti, and the holotype of the species was recovered from the same horizon

(Bed 1 locality 110) as M. (A.) falloti, specimen SAM-—PCZ5870. This seems to

indicate that, at that particular stratigraphic interval, Menabites (Australiella)

and M. (Delawarella) had already evolved into two distinct lineages. It is also

interesting to note the very large size of the Zululand specimen. This, to the

authors’ knowledge, is the largest texanitid recovered so far.

M. (D.) jeanneti resembles M. (D.) gigas in losing virtually all texanitid

ornament on the outer whorls (see Collignon 1948, pl. 31 (fig. 1-1b)), but

differs in having a more inflated whorl section.

M. (D.) subdelawarensis, another species known to grow to enormous size

in Zululand (p. 325), also differs in having a more inflated whorl section and

generally much finer ornament.

M. (A.) australis, which may also grow to enormous size, is easily dis-

tinguished by the long persistence of the trituberculate stage and also by the

more robust ornament.

The very large body chamber compared to the relatively small phragmo-

cone indicates that buoyancy control in this species must have been very delicate.

Occurrence

Campanian II of Zululand.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 339

Menabites (Delawarella) nibelae sp. nov.

Figs 259-261

Holotype

SAS-Z2101 (Figs 259-261), locality 110, south-western tip of the Nibela

Peninsula, Zululand, St Lucia Formation, probably Campanian iII.

Etymology

Named after the Nibela Peninsula at the northern side of Hell’s Gates,

connecting False Bay to Lake St Lucia.

Material

Only the holotype.

Dimensions

D Wb Wh Wb: Wh U Int L Ext

22101 164,0 67,0(40,8) 81,0(49,4) 0,83 37,0(22,6) 25 25 39

Description

Coiling is involute, with a very narrow umbilicus, measuring only 22 per

cent of the total diameter. The whorl section in the adult stage is higher than wide

(Fig. 261) with a vertical umbilical wall, and little inflated flanks converging to a

rounded venter. Inflation of the whorl increases with increasing diameter.

Where visible, ornament is subdued throughout, and consists of small

radially elongated umbilical (1) tubercles, a hardly visible lateral (2) and sub-

marginal (3) tubercle, poorly developed marginal (4) tubercle but prominent

external (5) tubercles, all situated on poorly developed radial to prorsiradiate

ribs. The ribs may be single, but the majority generally bifurcate at the sub-

marginal tubercle or arise as intercalatories at the marginal tubercles, giving

rise to many more external than internal tubercles. The keel is initially broad

and strong, but becomes indistinct towards the later part of the phragmocone

and on the body chamber.

Discussion

This species combines some of the characteristics of M. (D.) delawarensis,

M. (D.) subdelawarensis and M. (D.) jeanneti, pointing to the close relationship

between the various species.

The wide spacing of ribbing on the outer whorls is reminiscent of M. (D.)

delawarensis, the whorl section is that of M. (D.) subdelawarensis, whereas the

virtual absence of lateral (2) and submarginal (3) tubercles is reminiscent of

M. (D.) jeanneti. There is certain resemblance to the specimen described below

as M. (D.) sp. indet. (p. 342), but in the latter the whorl section is more inflated

at comparable diameters, and the keel is crenulate, compared to entire in the

present species.

340 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 259. Menabites (Delawarella) nibelae sp. nov. Holotype SAS—Z2101. x 0,88.

This is the M. (Delawarella) species with the narrowest umbilical width,

the next tightly-coiled species being M. (Delawarella) jeanneti with an umbilical

width of 24 to 29 per cent compared to 22 per cent in the former. Examination

of the whorl sections of the two species and details of ornament over the venter

at comparable diameters (see Collignon 1948, pl. 30 (fig. 3), pl. 31 (fig. 1))

clearly shows the differences. The whorl section of M. (D.) jeanneti is much

CRETACEOUS FAUNAS FROM SOUTH AFRICA 341

Fig. 260. Menabites (Delawarella) nibelae sp. nov. Holotype SAS-Z2101. x 0,94.

342 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 261. Menabites (Delawarella) nibelae sp. nov. Holotype SAS-—Z2101.

Showing whorl section. x 1.

more compressed, and at larger diameters tends towards weakening of the

external tubercles over the venter.

The exact horizon from which this specimen was collected at locality 110

is not known, but as far as the authors can recall, it was found high up in the

sequence, above the level of abundant menabitids. This could possibly indicate

yet another trend towards recoiling in the texanitids, possibly starting with a

relatively evolute form such as M. (A.) falloti through M. (Delawarella) jeanneti

to the present species.

Occurrence

Campanian of Zululand.

Menabites (Delawarella) sp. indet.

- Fig. 262

Material

SAM-PCZ5692, locality 110, south-western tip of the Nibela Peninsula,

Zululand, St Lucia Formation, Campanian II.

Description

A single septate specimen consisting of approximately a quarter of a

whorl is referable to M. (Delawarella), although specific identification is not

possible.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 343

Fig. 262. Menabites (Delawarella) sp. indet. SAM-PCZ5692. x1. .

344 ANNALS OF THE SOUTH AFRICAN MUSEUM

The whorl section is ovoid, wider than high with a prominent dorsal zone

of impression, a vertical umbilical wall and gently rounded flanks converging to

a broadly rounded venter. The keel is broad and low, and distinctly undulating,

though it is not quite clear if the undulations correspond to the external

tubercles.

Save slight undulations, all lateral ornament is absent, with only umbilical

(1) and external (5) tubercles present. The umbilical nodes are rounded to

slightly radially elongated. The external tubercles are clavate and obliquely

aligned in a forward direction. The ratio of external to umbilical tubercles is

of the order of three to one.

The suture is beautifully exposed as seen in Figure 262.

Discussion

Despite the fragmentary nature of this specimen, it differs from all known

Zululand specimens on account of the broad, undulating keel and rapid loss

of lateral ornament.

M. (Delawarella) subdelawarensis (see expecially Collignon 1948, pl. 29

(fig. 1)) has a comparable whorl section, but lacks the undulating keel and

strong attenuation of ornament. M. (Delawarella) delawarensis has an undu-

lating keel in later stages of growth, but is easily distinguished on account of

the strong ornament. M. (Delawarella) jeanneti is also somewhat similar in

attenuation of lateral ornament, but has a more compressed whorl section at a

comparable diameter (see Collignon 1948, pl. 30 (fig. 3)).

Hopefully further collection will permit definite identification of this

species.

Occurrence

Campanian II of Zululand.

Genus Spinaptychus Trauth

Figs 263-265

Type species

Aptychus spinosus Cox, 1926.

Description and discussion

The association of the aptychus form-genus Spinaptychus Trauth with the

genus Texanites was discussed on an earlier occasion by the authors (Kennedy

& Klinger 1972: 394-399; Klinger 1972: 105-109). Two texanitine specimens,

one of them referred tentatively to Texanites soutoni, were available to the

authors, and it was concluded that the association of Spinaptychus with Texa-

nites is real. Since then, three more aptychi have been found, either in body

chambers of, or associated with, texanitids, thus further establishing the rela-

tionship between Spinaptychus and Texanitinae.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 345

Fig. 263. Spinaptychus. SAM-K5551. Fragment of Spinaptychus in body chamber of

Plesiotexanites stangeri. X 1.

346 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 264. Spinaptychus. A. Silicone rubber mould of SAM—PCZ5876 (see Fig. 265).

B. SAM-PCZ5875. x 1.

347

CRETACEOUS FAUNAS FROM SOUTH AFRICA

SAM-PCZ5876. In body chamber fragment of Texanites soutoni

«1,15.

natalense ssp. nov.

Spinaptychus.

265

Fig.

348 ANNALS OF THE SOUTH AFRICAN MUSEUM

SAM-K5551 (Fig. 263), from locality 1 at Umzamba Cliff, Pondoland,

is a body chamber fragment of Plesiotexanites stangeri with part of one valve

of the aptychus preserved. The concentric striae clearly point to Spinaptychus.

SAM-—PCZ5875 (Fig. 264B) is a complete internal mould of the right valve

of a Spinaptychus from the Santonian/Campanian of locality 6 at the Enseleni

Reserve. The accompanying ammonoid fauna consists predominantly of

Pseudoschloenbachia umbulazi, Hauericeras gardeni and Texanites gr. ex. soutoni,

and Plesiotexanites stangeri. Of these, only T. soutoni is large enough to accom-

modate such a large aptychus.

SAM-PCZ 5876 (Fig. 265) is a virtually complete internal mould of the right

valve of a Spinaptychus in the body chamber of Texanites soutoni natalense,

from the Upper Santonian/Lower Campanian sediments at locality 105 on the

south-eastern shores of False Bay.

Unfortunately none of the specimens is sufficiently preserved for detailed

studies, but the sheer size and relative position of the aptychi still lead the

authors to regard Spinaptychus as possibly an operculum as well as a jaw-

apparatus as has been suggested for some uncalcified forms. especially anaptychi

(see Lehmann 1967, 1970, 1971, 1972, 1975).

Spinaptychus is now definitely known to occur with T. soutoni and P.

stangeri. As T. soutoni is transitional to Submortoniceras, it is to be expected

that the latter genus also bears spinaptychi.

EVOLUTION AND EVOLUTIONARY TRENDS IN TEXANITINAE

Details of the suggested evolution of the Texanitinae as indicated by the

South African material, and discussed in various sections of the systematic

descriptions, are outlined in Figure 266. These differ somewhat from Matsu-

moto’s (1955, 1965, 1970), Collignon’s (1948), and Young’s (1963) ideas, but

should be seen as complementary to their findings rather than revolutionary.

The origin of the Texanitinae is still not resolved. The earliest genus

appears to be Protexanites s.s., but data on the origin of the latter appear

conflicting. Matsumoto (1955: 39, 1970: 230) favours deriving Protexanites s.s.

from Subprionocyclus, and the authors concur in the case of species such as

P. bontanti, P. canaensis, and P. cycni, but have their doubts in the case of more

evolute, coarser-ornamented species such as P. bourgeoisi and P. shoshonense.

Some of the South African material seems to suggest that it would be possible

to derive Paratexanites via Protexanites, or both, from the aberrant Peroni-

ceratid ‘Fraudatoroceras’, but more material is needed to solve this problem

satisfactorily.

The root of texanitine radiation in South Africa appears to lie in Para-

texanites, especially the species P. australis, P. pseudotricarinatum, and

P. umkwelanense. Thus, from these, Protexanites (Pleurotexanites), Plesio-

texanites, and probably also part of Texanites s.s. may be derived. It is possible

CRETACEOUS FAUNAS FROM SOUTH AFRICA 349

CONIACIAN SANTONIAN CAMPANIAN

I] II

M.(A.) australis

M.(A) falloti

M.(D.) gigas

Protexanites cycni M.(D) delawarensis

M.(D.) subdelawarensis

M.(D.) aff. jeanneti

MD.) nibelae

snjoAd0u0ldgns

Menabites

Fraudatoroceras Bevahites

Tadd

Neogauthiericeras

SEIIDIUOIOY

Paratex. australis

Paratex. pseudotricarinatum

P collignoniforme ‘

T.umzambiense

T. presoutoni

P umkwelanense

T. soutoni

S.woodsi

S. condamyi

P aff. serratomarginatus

P aff. emsheris

Fig. 266. Suggested lines of evolution within Texanitinae as inferred from South African

material.

350 ANNALS OF THE SOUTH AFRICAN MUSEUM

to derive Bevahites from Pleurotexanites, which in turn may give rise to Mena-

bites s.1. This is basically the same view held initially by Matsumoto (1955: 43,

table 1), but lately he (Matsumoto 1970: 299) and Young (1963: 107) favour

the alternative of deriving Menabites (Australiella) from Protexanites. Matsu-

moto (1970: 299) also dismisses Pleurotexanites as an ancestor of M. (Australi-

ella), and considers these two taxa to be sibling offshoots of Protexanites s.s.

This view seems to be based on the alleged occurrence of two species of

Australiella, A. austinensis and A. sp. aff. pattoni, in strata of Santonian age.

Both these species lack precise stratigraphic data, and the authors prefer

deriving Australiella, Delawarella, and possibly Bererella via Menabites s.s.

from Bevahites, a view supported by the stratigraphic occurrence of these taxa

in Madagascar and Zululand.

Plesiotexanites may be regarded as a Paratexanites with a variably

developing lateral tubercle. Through fusing of the external (5) tubercles in

Plesiotexanites, the tricarinate venter of Reginaites may be derived. Develop-

ment in Reginaites tends towards discarding of the lateral (2) Plesiotexanites

tubercle, and possibly also a sharpening of the venter and gradual weakening

of the lateral keels, possibly resulting in Neogauthiericeras.

Plesiotexanites also probably gives rise to part of Texanites, e.g.

T. collignoni, and possibly T. umzambiense and T. texanus. Submortoniceras is

derived from Texanites through reduction of the umbilical diameter in the

South African material, and supports Young’s (1963: 90) views concerning the

relationsip between Texanites shiloensis and Submortoniceras tequesquitense.

Part of Texanites appears to be derived directly from Paratexanites without

passing through a Plesiotexanites stage, e.g. T. vanhoepeni and T. postvanhoepeni.

One distinct evolutionary trend noticeable in the South African texanitids

is the tendency towards reduction of umbilical width and ornament in younger

forms. A striking example of this is the sequence starting with T. umzambiense,

through 7. presoutoni and T. soutoni to Submortoniceras woodsi and S. condamyi

(Fig. 131). Another possible sequence is that of M. (Delawarella) subdelawarensis

through M. (D.) sp. aff. jeanneti to M. (D.) nibelae.

In addition, there appears to be a reduction of overall size in these two

lineages, but here the trend is not very distinct.

Through reduction of the umbilical width and ornament, and also overall

size and length of the body chamber, the shell becomes more streamlined and

consequently hydrodynamically stable. This seems to indicate a more active

mode of life, and, possibly, a deeper water habitat.

PALAEOBIOGEOGRAPHY

The palaeobiogeographic distribution of the Texanitinae during the Late

Coniacian to Early Santonian, Santonian s.l., and Early to Mid-Campanian,

as shown in Figures 267-269. is basicallv the same as that shown by Collignon

(1948: 52).

CRETACEOUS FAUNAS FROM SOUTH AFRICA 351

O PROTEXANITES

@ PARATEXANITES

60°

A TEXANITES

50°

40°

10°

20)

30)

40°

Fig. 267. Palaeobiogeography of Texanitinae during Coniacian to Early Santonian time

(Map after Smith et al. 1973, fig. 7.)

The geographic, as well as the biological origin (see p. 348) of the Texani-

tinae is obscure, and detailed stratigraphic collection is necessary to substantiate

Collignon’s assumption that radiation started in western Europe. Current data

show that Protexanites and Paratexanites species already occur in western and

central Europe, North Africa, the Gulf Coast region of North America, Hok-

kaido, and Zululand by Late Coniacian time. Wiedmann (1960), however,

reports Protexanites bourgeoisi, Protexanites cf. bontanti, and Protexanites

sp. nov. from the Lower Coniacian of the Vascogotic region of the Iberian

Peninsula, which may substantiate Collignon’s views. The rate of dispersion

thus seems to have been very rapid.

During Santonian time, four main regions of development were sheath

established: western and central Europe and the Middle East; the Gulf Coast

and adjacent areas of North America; Hokkaido and environs; and Mada-

gascar and South Africa; with minor centres in north Africa (Algeria), west

Africa (Nigeria and Cameroons), south-western Africa (Angola), and northern

South America (Venezuela and Peru). In terms of numbers and diversity, the

centre of maximum development appears to be Madagascar and South Africa.

352 ANNALS OF THE SOUTH AFRICAN MUSEUM

O PLESIOTEXANITES

@ REGINAITES

A TEXANITES

1 DEFORDICERAS

W@ BEVAHHES

® SUBMORTONICERAS

of 7@ MENABITES

8 ® PARATEXANITES

“SQ

Fig. 268. Palaeobiogeography of Texanitinae during Middle to Late Santonian time.

(Map after Smith ef al., 1973, fig. 7.)

Even though the majority of species in Santonian time appear to be endemic

to these four main regions, faunal exchange did take place on a limited scale,

as shown by the distribution of Plesiotexanites stangeri (Madagascar, South

Africa, Hokkaido, and Gulf Coast).

During Early and Middle Campanian times, endemism and development

of the Texanitinae seems to have reached its peak. Again Madagascar and

South Africa seem to have been the centre of development as exemplified by

the large number of Menabites s.1. and Submortoniceras species, even if excessive

taxonomic splitting is taken into account. In Europe, texanitine species decreased

numerically, and this region was now of subordinate importance to North

America and Hokkaido. Faunal interchange now was even more limited than

during Santonian time, and restricted to a few species, e.g. M. (Delawarella)

delawarensis (Zululand and North America), M. (Delawarella) campaniensis

(North America and Europe), Submortoniceras chicoense (North America and

Subantarctic Islands).

The demise of texanitids towards the end of Middle Campanian time

appears to have been virtually instantaneous, following a period of virtual

maximum development and occasional gigantism in Zululand, and no texani-

tids are known from the Upper Campanian sediments.

CRETACEOUS FAUNAS FROM SOUTH AFRICA 353

@ REGINAITES

O SUBMORTONICERAS

@ BEVAHITES

A MENABITES

60)

Fig. 269. Palaeobiogeography of Texanitinae during Early to Middle Campanian time.

(Map after Smith e¢ al., 1973, fig. 7.)

ACKNOWLEDGEMENTS

We are indebted to many persons and the institutes to which they are

attached for assistance in completing this study. First and foremost we wish

to express our gratitude to the late General M. Collignon, (Moirans) for assisting

us with many of the identifications and replying patiently to our numerous

queries, and we dedicate this work in his honour.

For further assistance in the form of constructive advice, material, litera-

ture and access to their collections we are grateful to Prof. Dr Jost Wiedmann

(Ttibingen), Mr C. W. Wright (Oxford), Dr M. K. Howarth and Mr D. Phillips

(British Museum, Natural History), Prof. R. A. Reyment (Uppsala), Dr Z. Lewy

(Jerusalem), Dr H. Kohl (Oberésterreichisches Landesmuseum, Linz), Prof.

K. Young (Austin), Drs C. K. Brain and E. Vrba (Transvaal Museum), Mr P. J.

Rossouw (Geological Survey, Pretoria), and Dr J. N. Theron (Geological

Survey, Cape Town).

For access to restricted areas and assistance in the field we are indebted to

the Natal Parks, Game and Fisheries Board, The Department of the Interior,

354 ANNALS OF THE SOUTH AFRICAN MUSEUM

Transkei, and the Geological Survey, Pretoria. Mr Johannes Nonyane provided

invaluable assistance during fieldwork in 1970 and 1971.

Assistance with illustrations by L. Scott, N. Eden, C. Hunter and V. Branco

of the South African Museum is gratefully acknowledged.

Financial assistance to H. C. Klinger was provided by the South African

Council for Scientific and Industrial Research; fieldwork by W. J. Kennedy in

1970 was financed by the Sir Henry Strakosh Bequest, and further research by

a grant from the Natural Environment Research Council (United Kingdom).

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113-147.

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SPATH, L. F. 1932. A monograph of the Ammonoidea of the Gault. Part 9. Palaeontogr. Soc.

[Monogr.] 84: 379-410.

SPATH, L. F. 1953. The Upper Cretaceous Cephalopod fauna of Grahamland. Sci. Rep.

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ZURCHER, P. 1905. Communication. Bull. Soc. géol. Fr. 5: 686.

. SYSTEMATIC papers must conform to the International code of zoological nomenclature

particularly Articles 22 and 5i).

Names of new taxa, combinations, synonyms, etc., when used for the first time, must be

ollowed by the appropriate Latin (not English) abbreviation, e.g. gen. nov., sp. nov., comb.

OV., Syn. nov., etc. .

An author’s name when cited must follow the name of the taxon without intervening

unctuation and not be abbreviated; if the year is added, a comma must separate author’s

lame and year. The author’s name (and date, if cited).must be placed in parentheses if a

pecies or subspecies is transferred from its original genus. The name of a subsequent user of

Scientific name must be separated from the scientific name by a colon.

Synonymy arrangement should be according to chronology of names, i.e. all published

cientific names by which the species previously has been designated are listed in chronological

rder, with all references to that name following in chronological ordez, e.g.:

Family Nuculanidae

Nuculana (Lembulus) bicuspidata (Gould, 1845)

Figs 14-15A

ucula (Leda) bicuspidata Gould, 1845: 37.

eda plicifera A. Adams, 1856: 50.

Laeda bicuspidata Hanley, 1859: 118, pl. 228 (fig. 73). Sowerby, 1871: pl. 2 (fig. 8a—b).

ucula largillierti Philippi, 1861: 87. :

eda bicuspidata: Nicklés, 1950: 163, fig. 301; 1955: 110. Barnard, 1964: 234, figs 8-9.

Note punctuation in the above example:

comma separates author’s name and year

semicolon separates more than one reference by the same author

full stop separates references by different authors

figures of plates are enclosed in parentheses to distinguish them from text-figures

dash, not comma, separates consecutive numbers

Synonymy arrangement according to chronology of bibliographic references, whereby

he year is placed in front of each entry, and the synonym repeated in full for each entry, is

ot acceptable.

In describing new species, one specimen must be designated as the holotype; other speci-

ens mentioned in the original description are to be designated paratypes; additional material

ot regarded as paratypes should be listed separately. The complete data (registration number,

pository, description of specimen, locality, collector, date) of the holotype and paratypes

ust be recorded, e.g.:

olotype

SAM-—A13535 in the South African Museum, Cape Town. Adult female from mid-tide region, King’s Beach

ort Elizabeth (33°51’S 25°39’E), collected by A. Smith, 15 January 1973.

Note standard form of writing South African Museum registration numbers and date.

. SPECIAL HOUSE RULES

apital initial letters

a) The Figures, Maps and Tables of the paper when referred to in the text

b) The prefixes of prefixed surnames in all languages, when used _in the text, if not preceded

by initials or full names

e.g. Du Toit but A.L.du Toit; Von Huene but F. von Huene

c) Scientific names, but not their vernacular derivatives

e.g. Therocephalia, but therocephalian

unctuation should be loose, omitting all not strictly necessary

eference to the author should be expressed in the third person

Roman numerals should be converted to arabic, except when forming part of the title of a

book or article, such as

“Revision of the Crustacea. Part VIII. The Amphipoda.’

pecific name must not stand alone, but be preceded by the generic name or its abbreviation

to initial capital letter, provided the same generic name is used consecutively.

ame of new genus or species is not to be included in the title: it should be included in the

abstract, counter to Recommendation 23 of the Code, to meet the requirements of

Biological Abstracts.

HERBERT CHRISTIAN KLINGER

WILLIAM JAMES KENNEDY

CRETACEOUS FAUNAS FROM ZULULAND

AND NATAL, SOUTH AFRICA

THE AMMONITE SUBFAMILY: TEXANITINAE

COLLIGNON, 1948

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