iT 1 JUNE 1982 | | ISSN 0303-2515

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ANNALS

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BULLOUGH, W. S. 1960. Practical invertebrate anatomy. 2nd ed. London: Macmillan.

FIsCHER, P.—H. 1948. Données sur la résistance et de le vitalité des mollusques. J. Conch., Paris 88: 100-140.

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

Zool. exp. gén. 74: 627-634.

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

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Konn, A. J. 19606. Spawning behaviour, egg masses and larval development in Conus from the Indian Ocean.

Bull. Bingham oceanogr. Coll. 17 (4): 1-51.

THEELE, J. 1910. Mollusca: B. Polyplacophora, Gastropoda marina, Bivalvia. In: SCHULTZE, L. Zoologische

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ANNALS OF THE SOUTH AFRICAN MUSEUM

ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM

Volume 89 Band

June 1982 Junie

Part 1 Deel

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A REVISION OF THE DEVONIAN

(EMSIAN-EIFELIAN) TRILOBITA

FROM THE BOKKEVELD GROUP OF

SOUTH AFRICA

By

MICHAEL R. COOPER

Cape Town Kaapstad

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Court Road, Wynberg, Cape Courtweg, Wynberg, Kaap

A REVISION OF THE DEVONIAN (EMSIAN-EIFELIAN)

TRILOBITA FROM THE BOKKEVELD GROUP

OF SOUTH AFRICA

By

MICHAEL R. COOPER

National Museum of Zimbabwe, Bulawayo

(With 120 figures)

[MS accepted 20 January 1982)

ABSTRACT

The Bokkeveld trilobite fauna is revised and shown to comprise the following species:

Ormistoniella malaca (Lake), Malimanaspis? dereimsi (Kozlowski), Burmeisteria herscheli

(Murchison), B. notica (Clarke), B. fontinalis (Reed), Francovichia clarkei (Ulrich), Gamon-

edaspis boehmi (Knod), Oosthuizenella ocellus (Lake), Pennaia pupillus (Lake), Metacryphaeus

caffer (Salter), M. venustus Wolfart, M. cf. koukharskii (Baldis & Longobucco), Typhloniscus

baini Salter, Phacopina hexensis (Reed), P. lakei (Reed), P. cf. padilla Eldredge & Branisa,

Phacopina? sp. nov?, Renniella rossouwi gen. et sp. nov., Bainella africana (Salter),

B. arbuteus (Lake), B. cristagalli (Woodward), B. gamkaensis Rennie, Bainella sp. nov.,

Deltacephalaspis pseudoconvexus (Reed), and Kozlowskiaspis ceres (Schwarz). The affinities of

the fauna are clearly with Bolivia. Three new genera are proposed, the dechenellid Ormis-

toniella, and the calmoniids Oosthuizenella and Renniella, as well as the new calmoniid

subgenus Metacryphaeus (Wolfartaspis). The only new species is Renniella rossouwi. At this

stratigraphic level Digonus and Burmeisteria are inseparable, and the former taxon is herein

considered superfluous; it is treated as a junior subjective synonym of Burmeisteria s.s. Higher

calmoniid taxonomy is unsatisfactory and in need of phylogenetic analysis. The trilobite

assemblages from the Gydo, Voorstehoek and Waboomberg Formations are distinct, and form

the basis for the recognition of the Bainella africana, Metacryphaeus caffer, and M. venustus

Assemblage Zones respectively. Commencement of Bokkeveld sedimentation is related to late

Emsian eustatic transgression, an age determination supported by the trilobite faunas, with

marine deposition extending well into the Eifelian.

CONTENTS

PAGE

PH EL OCUCHION er oA areata es ie eatin ernie ke te eens 2

SVSLOMIALICS terse ne etre ane iteens terete nine amet ded) tan eubuenie eh 5)

BamilyDechencellidactere, armen tens re acme eee 5)

Genus Crmistoniellacen, NOV «5. ne ae 5

Ramilva@tanomdaeerr. =e meer ee 14

GenlsHVMahianaspis® eerie ts ee ein 14

Bamilyaomalonotidactartwre acarics cr: pacer rs ee 17

GENUSES UIICISICLIG einen ee iain yt oe cen mee 17

HamilyeDalmaniti dace rites rete ee ea ee 45

Genustirancovichian ae re re 45

BamilyaSyvophoni dace steer an we ee 51

GenusiGamoedasp ism een yer ra 55

anulyi@almonnddes sce. ars Merny ite en foe eee 61

GenustOosthuizencila cen Ove sec. ee 63

1

Ann. S. Afr. Mus. 89 (1), 1982: 1-174, 120 figs.

2 ANNALS OF THE SOUTH AFRICAN MUSEUM

PAGE

GenusiPenndia s. a ocudc poeta Rie ees SEE 72

(CENWS MAME OOS coascsccveccosve0cac0nc0cccc 84

GENUS INHUDANELS coccocboocooc0psssccusEKdoKC 109

(GENUS JAVED DAG 000000000009 cd000000n0000000000 113

Genus (Rag wAlG BAMs WOT. bocccecccca0cc0K0000 006 124

GenuspBainclla ee. ay tise e soe eee eR oe N27

GenusvKOzlowsiiaspise seen eee a eee ace 155

Genus! Deltacephalaspiswerem nn eee ee 158

Biostrationaphyerye eerche sch soci ae Make Oo oe eee eet 161

Eaunaltattinities#) 2. Agi. oer. ce es ean a 163

Age ofthe BokKeveldifaunas) qers.o2 eee eee 167

SUMIM ALY eras ore errs acre eae eine aie eae 170

ACknOWledgements ane. cet eee pads case Ieee 170

IRNEfEEN CES Heresy hereon eae a eR oe SOR ee 171

INTRODUCTION

On 25 May 1836 Sir Roderick Murchison announced to the Geological

Society of London the discovery by Sir John Herschel of trilobites *. . . in rocks

which occur to the north of the Cape of Good Hope’, associated with other

fossils which, together, ‘. .. were found in abundance in the Cedar Bergen,

according tc Captain Alexander 150 English miles north of Cape Town and 2 000

feet above the sea, in an ash-grey quartzose sandstone’ (Sandberger 1853: 581).

The trilobites were subsequently identified by Murchison (1839) as Homalonotus

herscheli sp. nov. and Calymene blumenbachi Brongniart, the latter a

misidentification of what is now Oosthuizenella ocellus (Lake) (see p. 65). It was

Salter (1856), however, who was the first to describe a major collection of

invertebrate fossils from the Bokkeveld succession, including the trilobites

Homalonotus herscheli Murchison, Phacops (Cryphaeus) africanus sp. nov.,

Phacops caffer sp. nov., and Typhloniscus baini gen. et sp. nov. Thus, this work

is important in providing the first descriptions of the wholly Malvinokaffric

trilobite genera Bainella, Metacryphaeus, and Typhloniscus. In his subsequent

monograph of the British trilobites, Salter (1865) created the new subgenus

Burmeisteria within Homalonotus, with H. herscheli as the type species.

Woodward (1873) described a highly ornate trilobite with long axial spines

from the Cockscomb Mountains in the eastern Cape as Encrinurus cristagalli

sp. nov., whilst Schenk (1888) mentioned a ‘Praetus ricardi’ from the same

locality, but without figure or description and hence the name is a nomen

nudum. In 1897 Frech figured a specimen from the ‘Cape Colony’ as Homalo-

notus perarmatus sp. nov.

In the first work devoted entirely to a study of the Bokkeveld Trilobita,

Philip Lake (1904) recorded the following species: Phacops pupillus sp. nov.,

P. arbuteus sp. nov., P. ocellus sp. nov., P. africanus Salter, P. cristagalli

(Woodward), P. (Cryphaeus) caffer Salter, Typhloniscus baini Salter, Dalman-

ites lunatus sp. nov., Proetus malacus sp. nov., Homalonotus herscheli Mur-

chison, H. quernus sp. nov., and H. colossus sp. nov., and considered

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 3

H. perarmatus Frech a synonym of H. herscheli. Soon afterwards Schwarz

(1906) further added to the list of Bokkeveld trolibites when describing the

material housed in the Albany Museum, Grahamstown, including Phacops

cristagalli (Woodward), P. acacia sp. nov., P. (Cryphaeus) callitris sp. nov., P.

(C.) ceres sp. nov., P. (C.) gydowi sp. nov., Proetus ricardi Schenk, Homalono-

tus herscheli Murchison, H. perarmatus Frech, H. lex sp. nov., H. agrestis sp.

nov., H. horridus sp. nov. and H. hippocampus sp. nov.

In a discussion of the Bokkeveld fauna, Reed (1907) pointed out that the

subgenus Cryphaeus could not be applied to trilobites for reasons of priority,

and noted that the Bokkeveld phacopids fell into two groups. For Phacops

caffer, P. ocellus, P. impressus, P. callitris, P. gydowi, and P. ceres he proposed

the name Metacryphaeus, while considering P. africanus, P. acacia, P.

arbuteus, and P. cristagalli to ‘... fall into another group which in many

respects resembles that containing Dalmanites anchiops Green’ (p. 168). For

the latter group he proposed the name Anchiopella.

In describing Pennaia africana sp. nov. from Osplaats in the Hex River

valley, Shand (1914) was the first to report the presence of this genus in the

Bokkeveld fauna although, as noted by Rennie (1930), the species was generi-

cally misidentified. In a discussion of the genus Homalonotus, Reed (1918)

referred all the South African species to the subgenus Burmeisteria.

The most comprehensive discussion of the Bokkeveld Trilobita till now is

Reed’s (1925a) monographic ‘Revision of the fauna of the Bokkeveld Beds’ in

which he described or discussed the following taxa: Proetus malacus Lake,

P. hexensis sp. nov., Cyphaspis dereimsi Kozlowski, Dalmanites (Anchiopella)

africanus (Salter), D. (A) cristagalli (Woodward), D. (A.) arbuteus (Lake), D.

(A.) baini sp. nov., D. (Corycephalus?) capensis sp. nov., D. (Hausmannia)

lunatus Lake, D. (H.) dunni sp. nov., D. (Proboloides) ensifer sp. nov., D.

(Acastella?) pseudoconvexus sp. nov., D. (Cryphaeus) caffer (Salter), D. (C.)

caffer var. albana var. nov., D. (C.) cf. pentlandi Salter, D. (C?) cf. rostratus

Kozlowski, D. (C?) ceres (Schwarz), Phacops (Calmonia) callitris Schwarz, P.

(C.) impressus Lake, P. (C?) lakei sp. nov., P. (C?) pupillus Lake, Phacops

(Pennaia) gydowi Schwarz, P. (P.) africanoides nom. nov. (pro Pennaia afri-

cana Shand), P. (Phacopina) hiemalis sp nov., Homalonotus (Burmeisteria)

herscheli Murchison with the varieties colossus Lake, rectisuturalis var. nov.,

fusiformis var. nov., grahami var. nov., bituberculata var. nov., perarmata

Frech, and sodalis var. nov., H. (B.) quernus Lake, H. (B?) hippocampus

Schwarz, H. (Digonus) fontinalis sp. nov. and H. (D.) noticus var. africana var.

nov. Reed (19255) subsequently proposed the new genus Eocorycephalus to

include Dalmanites (Corycephalus?) capensis Reed from the Bokkeveld

sequence.

In reviewing work on the Phacopidae, Reed (1927) contended that Pha-

cops (Cryphaeus) caffer Salter, which he had earlier listed as a species of

Metacryphaeus, was, in fact, a typical Asteropyge and, since the remaining

species cited in his original proposal of the genus Metacryphaeus could all

4 ANNALS OF THE SOUTH AFRICAN MUSEUM

satisfactorily be included in Calmonia, the name should be abandoned.

Moreover, he stated that ‘. . . the type which was chosen for this special group

(Anchiopella) and exemplified by Dalmanites anchiops Green was Phacops

crista-galli (Woodw.)’ (p. 210), while now referring Phacops gydowi and Acaste

verneuili d’Orbigny to the genus Pennaia.

Rennie’s (1930) revision of the Bokkeveld ‘phacopids’ was important for

its attempt to stabilize nomenclature. Thus he showed that Metacryphaeus was

a valid taxon whose type species was Phacops caffer, that Eocorycephalus was a

junior subjective synonym of Synphoria, and that Eocorycephalus capensis

(Reed) was founded upon damaged cephala of Metacryphaeus caffer. Rennie

also transferred all Reed’s (1925a) Bokkeveld species of Dalmanites

(Anchiopella) to his new genus Bainella, because he erroneously believed (see

Cooper 1982) Dalmanites anchiops Green to be the type species of Anchiopella.

In this work Rennie (1930) described and/or figured Dalmanites (Metacry-

phaeus) caffer (Salter), D. (M?) ceres (Schwarz), Acaste (Pennaia) impressus

(Lake), A. (Calmonia) callitris (Schwarz), A. (C.) africana (Shand), Bainella

bokkeveldensis sp. nov. B. gamkaensis sp. nov., B. acacia (Schwarz), B?

africanus (Salter), and Typhloniscus baini Salter.

In 1951 Brink figured and described a large trilobite eye from the Bokke-

veld Beds that was identified only as Phacops sp. Pillet (1954) discussed the

classification of the phacopid trilobites and created the new genus Paradalman-

ites for Phacops acacia Schwarz. Paradalmanites was correctly included in the

synonymy of Bainella by Struve (in Harrington et al. 1959) who also rightfully

elevated Metacryphaeus, Calmonia, and Pennaia to generic status.

Although not dealing directly with the Trilobita from the Bokkeveld

succession, the works of Wolfart (1968), Branisa & Vanék (1973), Eldredge &

Ormiston (1979), and Eldredge & Brani§a (1980) on the Bolivian faunas have a

direct bearing on the classification of the Bokkeveld material. Wolfart’s (1968)

important study showed that Metacryphaeus caffer in South America was a

catch-all for a number of well-defined species of Metacryphaeus, thus pointing

to the impressive speciation and adaptive radiation that occurred in the strongly

transgressive deposits of the Malvinokaffric Realm. Branisa & Vanék (1973)

created a number of new calmoniid and dalmanitid genera, some of which are

now known also to occur in South Africa. Eldredge & Ormiston (1979)

reviewed the Malvinokaffric faunas and provided a tentative modern supraspe-

cific revision of the Bokkeveld fauna. Salient features of this review include

reference of Dalmanites dunni to the genus Francovichia, Proetus malacus to

Dechenella?, Phacopina hiemalis to Bainella?, Proboloides ensifer to Schizo-

stylus (Curuyella), the eye figured by Brink (1951) to the genus Fenestraspis,

and Cyphaspis dereimsi to Otarion (Maurotarion). The study of Eldredge &

BraniSa (1980) is of the utmost importance to an understanding of calmoniid

taxonomy, again highlighting the complex speciation that occurred in this

closed evolutionary pool. These workers provided a revised diagnosis of

Bainella and created the new subgenus B. (Belenops) to include Bainella

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 5

gamkaensis Rennie. They also figured a cephalon of Bainella bokkeveldensis

Rennie, and provided a schematic representation of the auxiliary impression

system of a Pennaia from Gamkapoort.

As it is now 50 years since the last paper was published dealing specifically

with Bokkeveld trilobites, the group is obviously in need of modern revision.

This is emphasized by the study of Eldredge & BraniSa (1980), which has

shown the Malvinokaffric trilobites to be largely endemic. Thus, such European

taxa as Acaste, Phacops, Dalmanites, Homalonotus, and Otarion are not

present in the Bokkeveld fauna, but are represented by closely allied or

homoeomorphic taxa. The aim of this paper is, therefore, to provide a modern

revision of the Bokkeveld fauna on the basis of type and additional material. In

this way it is hoped to recognize any zonal succession that may exist and, if

possible, to attempt to date the Bokkeveld succession on the basis of the

trilobite faunas.

The following abbreviations are used to indicate the repositories of

material discussed in the text:

AM _ Albany Museum, Grahamstown

BPI Bernard Price Institute for Palaeontological Research, Johannes-

burg

BM _ British Museum (Natural History), London

KM Alexander Macgregor Museum, Kimberley

PEM Port Elizabeth Museum, Port Elizabeth

PRV _ Geological Survey, Pretoria

RO Roy Oosthuizen Collection, Zwartskraal, Prince Albert

SAM_ South African Museum, Cape Town

SMC Sedgewick Museum, Cambridge

SU Geological Collections, Stellenbosch University

SYSTEMATICS

Order PROETIDA Fortey & Owens, 1975

Superfamily PROETACEA Salter, 1864

Family Dechenellidae Pribyl, 1946

Genus Ormistoniella gen. nov.

Type species Proetus malacus Lake, 1904;

by original designation herein

Etymology

For Allen R. Ormiston of Amoco Production Company, Tulsa, who

assisted the writer with literature pertaining to this species and who has

contributed greatly to an understanding of the dechenellid trilobites.

6 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis

Cephalon semicircular with very prominent, long, genal spines. Glabella

pear-shaped, tapering anteriorly. Glabellar furrows weak to obsolete; 1p

deepest, with weak adaxial branches tending to isolate L1. Preglabellar field

lacking. Eyes large, crescentic, close to axial furrows. Facial sutures strongly

divergent anteriorly. Thorax with 9 segments. Pygidium macropygous, oval,

elongate, with narrow but distinct border. Axis with 14-16 rings and pleural

fields with 6-7 pairs of ribs. There is a short post-axial field.

Discussion

Ormistoniella gen. nov. differs from Dechenella (Dechenella) in having less

deeply incised glabellar furrows, lacking a marked angulation of the anterior

facial sutures at the border furrow, possessing only 9 thoracic segments, and

with a pygidium with only 6—7 ribs in the pleural field and a very narrow

post-axial border. It is perhaps closest to D. (Basidechenella) which it resem-

bles in the shallowness of the glabellar furrows and very weak preoccipital

lobes, but may be distinguished by fewer thoracic segments and pleural ribs to

the pygidium and with a much narrower pygidial border. Ormistoniella may be

distinguished from D. (Monodechenella) by its pear-shaped glabella and fewer

pleural ribs to the pygidium.

It is clear from the above that Ormistoniella gen. nov. is closely allied to

Dechenella and that the differences may warrant only subgeneric separation, a

procedure originally favoured by the writer. However, in view of the constancy

of the count of 10 thoracic segments in all other known dechenellids, the

presence of only 9 in Ormistoniella malacus seems to be meaningful taxonomi-

cally. As such the differences are herein considered sufficient for generic

separation.

Ormistoniella malaca (Lake, 1904)

Figs 1-4, 5C, 6B, 7C

Praetus ricardi Schenk, 1888: 227 (nomen nudum).

Proetus malacus Lake, 1904: 213, pl. 25 (fig. 10). Reed, 1925a: 119, pl. 11 (fig. 3).

Proetus ricardi Schenk, Schwarz, 1906: 390, pl. 10 (fig. 5).

Dechenella? malaca (Lake) Eldredge & Ormiston, 1979: 164.

Material

The holotype, by monotypy, SAM—K559, together with SAM-—PDB 4203,

AM-35, SU-K460, RO-8, 412, 748, 759-761, 830, 832, P55—-56, C27, E4, 13,

63, 68, PRV-—26, 71, and an unnumbered KM specimen.

Description

Cephalon. The cephalon is semicircular, much wider than the sagittal

length, and with long genal spines extending backward as far as the 5th or 6th

thoracic segment. The lateral and anterior borders are broad, well developed,

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 7

Fig. 1 Ormistoniella malaca (Lake).

A reconstruction based upon the available material. x 2.

and striated along their lengths. The rather shallow lateral border furrows meet

the moderately deep posterior border furrows in very acute angles at the bases

of the genal spines and are produced backward almost to their distal tips. The

occipital furrow is narrow and deep, and the occipital ring is of uniform width.

The glabella is urceolate, waisted opposite the 3p furrows, very broad and short

with a maximum transverse width slightly less than the sagittal length, and

tapers rather strongly to the anterior. The axial furrows are shallow, especially

opposite the eye lobes. Glabellar segmentation is poorly developed; 3p is faint,

very short, and almost normal to the glabellar margin; 2p is slightly longer and

weakly curved but equally indistinct; 1p is the deepest, but still weakly

developed, and curves back almost to the occipital furrow, so as to separate a

subtrigonal, incipient preoccipital glabellar lobe (L1). The lp furrows show a

faint but distinct adaxial bifurcation. The glabella reaches to the anterior

furrow and there is no preglabellar field. The eyes are fairly large, holochroal,

and comprise hundreds of extremely small ocelli arranged in diagonal rows.

8 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 2. Ormistoniella malaca (Lake). The holotype, by

monotypy, SAM-PDB559, preserved as an internal

mould. Note the broad pygidial axis. x 1,7.

Thorax. The thorax comprises 9 segments only (Fig. 7C) with a well-

defined, strongly convex axis. The pleural fields are strongly down-turned

distally, with well-defined fulcra. There are deep, prominent pleural grooves to

the pleurae, which are separated by finer interpleural furrows.

Pygidium. Large, macropygous, oval in outline, and somewhat wider than

the sagittal length. As with the British dechenellids (cf. Selwood 1965) there

are two morphotypes amongst the pygidia, the differences perhaps reflecting

sexual dimorphism. In the Type I pygidia (Fig. 3D) the moderately convex axis

is rather broad, tapering fairly rapidly to the posterior, and comprises 14-16

distinct axial rings. In the Type II pygidia (Fig. 7C), the axis is relatively much

narrower, more convex and tapers less strongly to the posterior. In both types,

the pleural fields are moderately convex, subtrigonal, down-turned distally and

with 6-7 prominent ribs separated by equally broad pleural furrows. The

pleural ribs become obsolete distally so as to leave a narrow, smooth border

with an entire margin. There is a narrow post-axial field which is terminally

acuminate.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 9

Fig. 3. Ormistoniella malaca (Lake). A. RO-760. B-—C. RO-748, an enrolled specimen.

D. RO~-761. Note the broad pygidial axis. E-F. An enrolled specimen, unnumbered, in the

Alexander MacGregor Museum. G. RO-P55. H. RO-P56. I. RO-90, an unusually large

individual. All preserved as internal moulds and all x 1.

10 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 4. Ormistoniella malaca (Lake). Lateral view of RO-8,

preserved as an internal mould. x 3.

Discussion

No other dechenellids are currently recorded from the Malvinokaffric

Realm and hence O. malaca is easily distinguished. *“Proetus’ hexensis Reed

(1925a: 121, pl. 7 (fig. 8)) is based upon pygidia which differ from O. malaca in

being semicircular in outline, with fewer axial rings and pleural ribs, indistinct

segmentation and a distinct post-axial field.

‘Proetus’ problematicus Swartz (1925: 56, pl. 1 (figs 3-5)) is based upon

fragmentary material from Bolivia that shows this species to be micropygous

and thus probably an otarionid. Dechenella (Basidechenella?) boteroi Caster &

Richter (in Richter & Richter 1950: 161; Eldredge & Ormiston 1979: 164) from

the Devonian Floresta Beds of Colombia has median tubercles to the axial rings

of the pygidium, 9 pairs of pleural ribs that are also tuberculate, and a broad,

flattened border and hence is not liable to be confused with the present species.

‘Proetus’ chengi Sun (1937: 350, pl. 1 (fig. 2)) from the Upper Devonian

Hsikuangshan Formation of Hunan, China, resembles O. malaca in the outline

and narrow border of the pygidium, and with ‘13 or more’ axial rings, but its

axis tapers more rapidly to the posterior and there are said to be 12 pairs of ribs

in the pleural fields.

11

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

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12 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 6. A. Deltacephalaspis pseudoconvexus (Reed). The lectotype, designated herein,

SAM-7201, preserved as an internal mould. x 1,9. B. Ormistoniella malaca (Lake). SAM-

PDB4203, preserved as an internal mould. x 1,2. C. Pennaia pupillus (Lake). SAM—9605,

preserved as an internal mould. x2. D. Metacryphaeus caffer (Salter). SAM-—PDB4347, an

internal mould. x 1,1.

Boliviproetus branisai Eldredge & Ormiston (1979: 163, pl. 1 (figs 1-7))

has a strongly inflated cephalon with a narrow preglabellar field. The strongly

inflated glabella is oval in outline, not urceolate as in O. malaca. The pygidium

of B. branisai is readily distinguishable from that of O. malaca in its weak axial

segmentation and effaced axial furrows, with all but the first interpleural

furrows obsolete.

Dechenella clara (Hall) (Hall & Clarke 1888: 104, pl. 20 (figs 12-14), pl. 22

(figs 28-30)) from the Onondaga Limestone bears a general resemblance to O.

malaca, but possesses pronounced occipital lobes and a pygidium twice as wide

as long, with 7-11 axial rings and 4-5 pleural ribs.

Dechenella mackayi Allan (1935: 27, pl. 1 (fig. 2)) from the Reefton Beds

of New Zealand resembles O. malaca in its multisegmented pygidial axis with

12-15 axial rings and pleural fields with 7-8 pairs of ribs. It differs, however, in

having an elliptical outline to the pygidium, pleural ribs that are much wider

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 13

Fig. 7. A. Gamonedaspis boehmi (Knod). PRV-126a, an internal mould. x 2,6. B. Typhlo-

niscus baini (Salter). PRV-625, preserved as an internal mould. x 2,4. C. Ormistoniella

malaca (Lake). PRV-71, an internal mould. Note nine segments to thorax and narrow pygidial

axis. X 3.

14 ANNALS OF THE SOUTH AFRICAN MUSEUM

than the intervening furrows and with distinct pleural grooves, and in possess-

ing granulose ornament.

Occurrence

Ormistoniella malaca (Lake) is common in the Gydo Formation, while a

single specimen, PRV-26, in green shale preservation may be from the

Voorstehoek Formation.

Family Otarionidae Richter & Richter, 1926

Subfamily Otarioninae Richter & Richter, 1926

Genus Malimanaspis Baldis & Longobucco, 1977

Type species Malimanaspis sarudianskii Baldis & Longobucco;

by original designation

Malimanaspis ? dereimsi (Kozlowski, 1923)

Fig. 8

Cyphaspis dereimsi Kozlowski, 1923: 61, pl. 4 (figs 15-17). Swartz, 1925: 34. Reed, 1925a: 12,

pl. 10 (fig. 10).

Otarion dereimsi (Kozlowski) Branisa, 1965: 96, pl. 16 (figs 29-30).

Otarion (Maurotarion) dereimsi (Kozlowski) Eldredge & Ormiston, 1979: 165.

Malimanaspis dereimsi (Kozlowski) Baldis & Longobucco, 1977a: 154.

Material

SMC-A3062a, obtained from a road cutting between De Doorns and

Tunnel (Reed 1925a), is still the only example known from the Bokkeveld

Group.

Description

Cephalon. The cephalon is semicircular, with the anterior border slightly

pointed sagittally, about twice as wide as the sagittal length, and with pro-

minent genal spines extending backward to about the fourth thoracic segment.

There is a well-developed preglabellar field, with a broad, fairly deep anterior

furrow and a convex anterior border. The lateral borders to the cephalon are

also very broad. The glabella is strongly inflated, trapezoidal in outline, almost

rectangular, with maximum width at the occipital furrow. The deep, well-

developed Ip glabellar furrows curve strongly backward to separate pro-

nounced pre-occipital lobes (L1). L1 is half the exsagittal length of the glabella,

whilst the 2p and 3p furrows are obsolete. The glabella is surrounded by deep,

narrow axial and preglabellar furrows. The occipital furrow is rather narrow,

anteriorly convex, and separates off an occipital ring of constant width.

Although the eyes are missing from the present specimen, their broken bases

suggest they were moderately large. The anterior branches of the facial suture

are strongly divergent and the posterior branches extremely so, the latter

meeting the posterior margin somewhere in the genal spines.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP IS)

Fig. 8. Malimanaspis? dereimsi (Kozlowski). SMC-

A3062a, preserved as an internal mould. x 1,6.

Thorax. The thorax comprises at least 12 segments and has a broad axis,

about one-third of the thoracic width. The pleurae bear deep pleural grooves

and display prominent fulcra.

Pygidium. Unknown from the present material.

Discussion

The generic assignment of the Bokkeveld specimen poses some problems.

It was regarded as conspecific with the South American Cyphaspis dereimsi

Kozlowski both by Reed (1925a) and the writer. However, Baldis & Longo-

bucco (1977a) have recently assigned Kozlowski’s species to their new genus

Malimanaspis, distinguished by a pustulose ornament over the entire exoskele-

ton, which is reflected on internal moulds, the presence of a median tubercle to

the occipital ring, and median tubercles (spines?) to the thoracic axial rings,

and a pygidium with less than 5 axial rings. Kozlowski (1923) makes no

mention of pustulose ornament in his original description of Cyphaspis der-

eimsi, nor of the presence of a median tubercle to the occipital ring or sagittal

tubercles to the thoracic axis. Similarly, none of these features is evident in the

16 ANNALS OF THE SOUTH AFRICAN MUSEUM

Bokkeveld specimen, although the writer does not have the original for close

inspection. The cranidium figured by Wolfart (1968, pl. 1 (fig. 1)) and assigned

to Otarion dereimsi does, however, show pustulose ornament but, since there

are now known to be at least 2 species of otarionid in the Malvinokaffric

Realm, is perhaps better referred to Malimanaspis sarudianskii Baldis &

Longobucco. Clearly the problems surrounding Otarion dereimsi (Kozlowski)

can be resolved only by a restudy of the type material. The Bokkeveld example

is, therefore, only questionably assigned to the genus Malimanaspis, since it

also resembles Otarion (Maurotarion).

Amongst Bokkeveld species, the only possibility of confusion of Malima-

naspis ? dereimsi lies with Ormistoniella malaca (Lake). The latter species has,

however, an urceolate glabella that lacks the deep 1p furrows and well-

developed pre-occipital lobes of Malimanaspis? dereimsi, as well as being

macropygous.

Otarion (Maurotarion) maurum (Alberti) (1967: 500, pl. 1 (fig. 28);

1969: 384, pl. 36 (figs 1-4), pl. 46 (fig. 19)) is a Silurian (Lower Ludlow) species

from Morocco which differs from M? dereimsi in having relatively smaller

pre-occipital lobes, convex axial furrows to the glabella, a more strongly convex

preglabellar furrow, and a sagittal node to the occipital ring. Otarion (Mauro-

tarion) neptis (Alberti) (1969: 386, pl. 36 (figs 9-10)) is easily separated from the

present species by its elliptical glabella with relatively much smaller pre-occipital

lobes and much broader occipital ring with a sagittal node. These are also much

the same features that distinguish O. (M.) ambiguum (Alberti) (1969: 388, pl. 36

(fig. 11)), which also has a narrower anterior border not weakly pointed sagittally

as in M? dereimsi. Otarion (Maurotarion) elegantulum (Loven) (Alberti

1969: 384, pl. 36 (figs 5-6)) is a Silurian species with a pronounced anterior

border, which is distinctly pointed on the sagittal line, and with a strongly convex

preglabellar furrow, relatively smaller pre-occipital lobes, and a much broader

occipital ring than the present species. Other species referred to O. (Maurota-

rion) by Alberti (1969) include O. (M.) novellum (Barrande), O. (M.) instita

Whittington & Campbell, O. (M.) plautum Whittington & Campbell, O. (M?)

cristyi (Hall), and O. (M?) girardeauensis (Shumard), but the writer does not

have access to the literature pertaining to these species.

Kozlowski (1923) and Eldredge & Ormiston (1979) have pointed to the

similarity of this species with Otarion miniscula Hall (Hall & Clarke 1888: 140,

pl. 24 (figs 7-12)) from the Bois Blanc, Schoharie, and Onondaga of Ontario

and New York, from which it was distinguished by its larger size and stouter

genal spines.

Otarion tiaomachienensis (Sun) (1937: 349, pl. 1 (fig. 1)) has much smaller

pre-occipital lobes than the present species and its glabella is more strongly

inflated anteriorly, with a strongly convex preglabellar furrow.

‘Proetus’ problematicus Swartz (1925: 56, pl. 1 (figs 3—-5)) may be an

otarionid; it shows a small, subtrigonal pygidium that differs from that of the

present species in lacking trilobation and segmentation. The Cyphaspis sp. of

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 7)

Kozlowski (1923: 62, pl. 4 (fig. 18)) was assigned to Andinacaste legrandi sp.

nov. by Eldredge & Brani§a (1980).

Eldredge & Ormiston (1979) refer to a second species of Otarion in the

Belen Beds of Bolivia, which was said to show considerable resemblance to O.

(M.) novellum (Barrande). It was distinguished from M. dereimsi by its

semicircular cephalon and slender genal spines, relatively smaller pre-occipital

lobes, convex preglabellar furrow, narrow anterior and lateral borders, and

median node to the occipital ring. It must also, therefore, be very close to O.

(M.) ambiguum (Alberti).

Occurrence

Malimanaspis? dereimsi (Kozlowski) ranges from the zone of Bainella

insolita through to the Metacryphaeus giganteus Zone in Bolivia, but its level of

occurrence in South Africa is uncertain.

Order PHACOPIDA Salter, 1864

Suborder CALYMENINA Swinnerton, 1915

Family Homalonotidae Chapman, 1890

Subfamily Homalonotinae Chapman, 1890

Genus Burmeisteria Salter, 1865

Type species Homalonotus herscheli Murchison, 1839;

by original designation

Discussion

Two subgenera are currently recognized in this genus; they are Burmeis-

teria (Burmeisteria) with a supposedly urceolate glabella showing distinct loba-

tion and a biconcave rostral suture, and B. (Digonus) in which the trapezoidal

glabella lacks lobation and the rostral suture is transverse or slightly concave.

However, as remarked by Sdzuy (1957) and Saul (1965), the form of the rostral

suture is highly variable and thus of little taxonomic significance. This is

confirmed by the present study, which suggests its form may in part be

ontogenetically related and that the shape of the glabella and the strength of its

lobation cannot be used to distinguish B. (Burmeisteria) and B. (Digonus).

Indeed, available material of B. herscheli, the type of the genus, shows every

transition between these two subgenera and at this level the criteria on which

they were established do not appear to be of specific let alone subgeneric

importance. Consequently, the subgenus Digonus is herein considered a junior

subjective synonym of Burmeisteria s.s.

In providing the most recent discussion of this subfamily, Thomas (1977)

pointed to the similarity of the cephalon of Burmeisteria with that of juvenile

Dipleura and suggested that Burmeisteria may be a neotenous descendant of

Dipleura.

18 ANNALS OF THE SOUTH AFRICAN MUSEUM

Saul (1965) has suggested that this genus may be dimorphic, the dimorphs

distinguished by the characters of the pygidium. If present in B. herscheli

(Murchison), any such dimorphism is certainly inconspicuous and masked by

polymorphism.

Burmeisteria herscheli (Murchison, 1839)

Figs 9-13, 14A—-B, D-F, 15-28, 39E, 56H

Homalonotus herscheli Murchison, 1839: 652, pl. 7 (fig. 2). Salter, 1856: 215, pl. 24 (figs 1-8).

Lake, 1904: 214, pl. 26 (figs 1-3). Schwarz, 1906: 383, pl. 8 (fig. 8), pl. 9 (fig. 3). Clarke,

1913: 93, pl. 3 (figs 1-4).

Homalonotus perarmatus Frech, 1897: 218.

Homalonotus quernus Lake, 1904: 216, pl. 27 (fig. 1).

Homalonotus colossus Lake, 1904: 216, pl. 28 (figs 1-3).

Homalonotus sp., Lake, 1904: 217, pl. 27 (fig. 2).

Homalonotus herscheli Salter var?, Schwarz, 1906: 383, pl. 8 (fig. 8).

Homalonotus horridus Schwarz, 1906: 385, pl. 9 (fig. 1).

Homalonotus agrestis Schwarz, 1906: 386, pl. 9 (fig. 2).

Homalonotus hippocampus Schwarz, 1906: 388, pl. 9 (fig. 5).

Homalonotus lex Schwarz, 1906: 389, pl. 9 (fig. 4).

Homalonotus (Burmeisteria) herscheli Murchison, Reed, 1918: 314; 1925a: 163.

Homalonotus (Burmeisteria) herscheli var. rectisuturalis Reed, 1925a: 167, pl. 10 (figs 3, 7).

Homalonotus (Burmeisteria) herscheli var. colossus Lake, Reed, 1925a: 169.

Homalonotus (Burmeisteria) herscheli var. fusiformis Reed, 1925a: 171.

Homalonotus (Burmeisteria) herscheli var. grahami Reed, 1925a: 172.

Homalonotus (Burmeisteria) herscheli var. bituberculata Reed, 1925a: 173, pl. 10 (fig. 2).

Homalonotus (Burmeisteria) herscheli var. perarmata Frech, Reed, 1925a: 175.

Homalonotus (Burmeisteria) quernus Lake, Reed, 1925a: 181, pl. 9 (fig. 13), pl. 10 (fig. 1).

Homalonotus (Burmeisteria?) hippocampus Schwarz, Reed, 1925a: 183.

Homalonotus (Burmeisteria) sp., Reed, 1925a: 184.

Burmeisteria herscheli (Murchison) Saul, 1965: 271.

Burmeisteria hippocampus (Schwarz) Sdzuy, 1957: 283, fig. 1.

? Burmeisteria herscheli (Murchison) BraniSa, 1965: 84, pl. 10 (figs 1, 4), pl. 11 (fig. 6).

? Burmeisteria (Burmeisteria) sp., Wolfart, 1968: 61.

Material

Salter’s (1856) original material in the British Museum, abundant material

in the South African Museum including SAM-—7199, SAM-PDB598, 600, 619,

626-627, 1406, 4292-4293, 4343, 4345, 4352, 4356, 4359, 4360-4364, 7193, 7201,

7795-7796, SU-C6, D182, K810, AM-—1-2, 6, 8, 13, 21, 61-64, 1432, 1444,

1457, 1462, 1613, 1616, 2552-2554, together with RO-16, 175, 257, 271,

807-808, 810-812, 815-819, 825, E22, 50-52, 57-59, 72, 90-92, L20, 60, and 93.

Description

Cephalon. The cephalon is moderately to very convex (depending on the

size and the nature of preservation), with downturned cheeks and a subtrigonal

to trapezoidal outline. It is wider than the sagittal length, with a prominent

occipital furrow and fairly deep posterior border furrows that shallow abaxially.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 19

Fig. 9. Burmeisteria herscheli (Murchison). The original of Salter

(1856, pl. 24 (fig. 1)), preserved as an internal mould. x 1.

The lateral border furrows are very shallow and indistinct and there is no

anterior border furrow, although the whole of the preglabellar field is gently

concave. The preglabellar field is moderately broad, generally between 17-20

per cent of the sagittal length of the cephalon, and may be flattish or distinctly

upturned. The glabella is very slightly elevated and generally subtrapezoidal in

outline, though tending to urceolate in some individuals. The axial furrows are

moderately deep, diverging slightly to the posterior, whilst the anterior margin

of the glabella is abruptly truncate but still with rounded corners and a gently

convex preglabellar furrow. Glabellar segmentation is variably developed from

individual to individual, tending to be most pronounced in juveniles and

commonly very weak or obsolete in the middle and adult growth stages. The 3p

furrows are weak to indistinct, short, directed posteromedially and subparallel

to the slightly longer and more pronounced 2p furrows. The 1p furrows are

strongly curved adaxially, almost reaching the occipital furrow and tending to

separate weakly developed, subtrigonal, pre-occipital lobes. The occipital fur-

row is transverse, sometimes arched forward sagittally, and commonly nar-

rower than the occipital ring. The posterior borders broaden slightly abaxially

and commonly bear from_1 to 3 small dorsal spines (Fig. 22) just before the

rounded genal angles. The subtrigonal paraglabellar areas (Fig. 9) vary from

indistinct to prominent, tending to be more pronounced in larger individuals. In

some examples the paraglabellar areas tend to invade the L1 lobes, giving them

slightly concave lateral margins. The strongly convex cheeks bear prominent

rounded bosses on top of which are situated the small elevated eyes surrounded

by shallow circumocular furrows. The eyes are situated just posterior to the

20 ANNALS OF THE SOUTH AFRICAN MUSEUM

abaxial terminations of the 2p glabellar furrows. The rostral plate is triangular,

varying from equilateral to distinctly longer (sag.) than wide, and bears a

prominent, hooked, beak-like, median spine. The hypostoma (Fig. 39E) is

similar to that of Homalonotus but with only a very weak posterior indentation.

The facial suture is proparian, the posterior branches cutting the lateral margins

just in front of the genal angles. The anterior facial suture is highly variable,

with the rostral suture either transverse, concave or biconcave. This character

may be ontogenetically related (Fig. 23) since small individuals generally have a

concave rostral suture, while a biconcave suture is encountered only in mod-

erately large to large specimens. The entire surface of the cephalon is granu-

lose, with randomly scattered tubercles (Fig. 24) that vary in distribution from

individual to individual, but tend to be concentrated along the posterior

borders.

Thorax. The thorax comprises 13 segments with a very broad axis, which is

at least 60 per cent of the thoracic width. Ornament comprises scattered

granules and randomly distributed tubercles (Fig. 25), the latter tending,

however, to form a longitudinal row just inside the axial margins. As shown by

SAM-K1406, the tubercles represent spine bases (Fig. 56H). The axial furrows

are indistinct but marked by prominent pits at the adaxial ends of the interpleu-

ral furrows. The pleural furrows are deep, diverging abaxially from the anterior

borders of the pleurae (Fig. 17D), and terminate just before the truncate distal

margins of the pleurae.

Pygidium. The pygidium is strongly convex, triangular, longer than wide,

and with fairly distinct trilobation. The axis is triangular, rather broad an-

teriorly but tapering to the posterior and terminating before the posterior

margin is reached to leave a short post-axial field. In large individuals the axis

comprises 16-17 rings, with the segmentation tending to become indistinct for

the last few rings. On internal moulds the terminal point of the pygidium is

sharply rounded, acuminate. The axial rings are much wider than the ring

furrows and may, or may not, bear a few scattered tubercles (Figs 25-26), while

the entire cuticular surface of the pygidium is granulose. The pleural fields are

triangular, convex, and curved almost vertically downwards at their margins.

They are commonly ornamented with 9-11 pairs of low ribs that are wider than

the interpleural furrows. The ribs do not reach the lateral margins, leaving a

narrow entire border. The pleural grooves vary from very indistinct to obsolete.

Discussion

Since a species is defined on the basis of the characters of a population of

individuals, it is clear that the thirteen or so taxa of Burmeisteria currently

recognized in the Bokkeveld fauna represents a gross splitting of a small

number of variable species. Thus, it is readily apparent that B. herscheli

displays an extreme range of intraspecific variation and hence genetic poly-

morphism. This is most apparent in the characters of the tuberculation and it is

worth recalling Reed’s (1925a: 179) comment that *... the lack of bilateral

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 21

symmetry and the general irregularity in the distribution of the tubercles and

spine bases on the thorax and pygidium is a noticeable feature in all the forms

here regarded as varieties of H. Herscheli, and for this reason the tuberculation

must be regarded as of small specific or varietal value. Individuals, otherwise

identical, differ considerably in this respect’. The author agrees wholeheartedly

with this statement although the varietal rank is here used only for recurring

morphotypes that form a significant percentage of the individuals within a

contemporaneous population. With regard to the rostral suture, it has already

been noted that its form seems to be ontogenetically related and it is not herein

considered of specific importance. Similarly, the strength of the glabellar

segmentation is so variable, depending on ontogenetic stage and mode of

preservation, that it, too, does not appear to be of taxonomic importance

among the present material.

Burmeisteria herscheli was originally based upon a thorax and pygidium

(Murchison 1839, pl. 7 (fig. 2)), with the original of Salter’s (1856) plate 24,

figure 1 generally being regarded a typical cephalon. However, as noted by

Reed (1925a), Salter’s figure is a restoration based upon more than one

individual since the original of his figure 1 (Fig. 9) lacks the occipital ring and

posterior borders.

Lake (1904) introduced Homalonotus colossus for a very large but frag-

mentary cephalon that Clarke (1913: 95) considered to be merely a large B.

herscheli. Reed (1925a: 170), however, felt that‘... it may be worthy of being

a variety, for there are more numerous (5) tubercles or spine bases on the

pleuro-occipital rings, and the thoracic segments bear 2 pairs of lateral spines or

tubercles’. As can be seem from Figures 24-26, however, the distribution of

tubercles in B. herscheli is highly variable and the use of this character, even at

the varietal level, would result in a superfluous multiplicity of names. Conse-

quently, the writer follows Clarke (1913) in considering H. colossus a junior

subjective synonym of B. herscheli.

Homalonotus quernus Lake (Fig. 27A) was based upon a very large

fragmentary specimen showing coarse tuberculation on the glabella and thorax.

Since, however, there are transitional forms to the sympatric B. herscheli

(Fig. 24), the differences are not herein considered of specific importance,

although Lake’s name may usefully be retained at the varietal level for the

hypernodose individuals within B. herscheli populations. As suggested by Reed

(1925a), the fragmentary pygidium figured by Lake (1904: 217, pl. 27 (fig. 2))

as a Homalonotus sp. (Fig. 27B) should be assigned to this variant.

Homalonotus perarmatus Frech (Fig. 20) and H. horridus Schwarz are both

multituberculate ‘species’ transitional from B. herscheli s.s. to the var. quernus.

Consequently, the writer would agree with Lake (1904) and Reed (1925a) in

regarding H. perarmatus as a junior subjective synonym of B. herscheli, as well

as following Reed (1925a) in including H. horridus Schwarz in the synonymy of

Murchison’s species. The retention of these names even at the varietal level

serves little practical purpose and they are not used here.

ANNALS OF THE SOUTH AFRICAN MUSEUM

Up)

jenjen) wnasnyy ysnig

“ST X ‘pjnow jeusdjuUI ue se paarasaid ‘(A10]SIH]

ay) ut ‘((Z ‘3Yy) pz Id ‘ggg]) JaIeSg Jo JeuIsiIo oy, ‘(UOSTYyoIN|,) ayossay pDlualsiawung “QT “3I4

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP M8;

Fig. 11. Burmeisteria herscheli (Murchison). The original of

Salter (1856, pl. 24 (fig. 4)), in the British Museum (Natural

History), preserved as an internal mould. This specimen was

referred to the var. perarmata Frech by Reed (1925a). x 1.

Homalonotus agrestis Schwarz (1906: 386) was distinguished by ‘ . . . the

very rapid tapering of the pygidium and the incurved margin’ but, as noted by

Reed (1925a: 178), is so similar to H. horridus that it, too, is included in the

synonymy of B. herscheli. Homalonotus hippocampus Schwarz was based upon

a number of small cephala distinguished by their subtrigonal outlines and flat

glabellae. According to Reed (1925a: 183), however, * ... the shape of the

glabella, the practical absence or obsolescence of the lateral furrows on its

ANNALS OF THE SOUTH AFRICAN MUSEUM

24

“Tl x IP pue sp[nou [Buto}UL se poarasaid ITV “SIJDANINSIIIA “IVA oq} Oj Ppoltojol a ‘3y) Ol ‘Id “DCZ6I S,Pp9I9y jo [BUIsIIO oy) “C6ILHdd-WNVS “Ste D)

“QINJNS [PIISOI DAKIUOD dy) ION ‘ZIEPACd-NVS “A ‘Wowsesy yerpistd ve ‘76z7pPadd-NVS “V “(UOSTYoINI) Yayosiay YLaIsiaULng “7 “B14

25

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

Wek [Ihe

pure spjnow jeusajur se paarasaid Ty “S6LLUAdd-WVS ‘O ‘09¢PAdd-WVS “A ‘C9EhAdd-WVS 'V ‘(UOSIYOINIA]) YaYyISday Dldajsiauing “¢] “3I4

26 ANNALS OF THE SOUTH AFRICAN MUSEUM

surface, the straight, transverse, connecting suture in front, the presence of a

pair of spine bases close to the genal angles, and other features suggest that it is

only a young individual or narrow form of H. herscheli var. rectisuturalis. In the

Ordovician trilobite Ogygia buchi Brongniart we have a narrow and a wide

form, the differences being regarded as sexual. Possibly the same explanation is

applicable here.’ Perhaps significantly, Saul (1965) has recorded size dimorph-

ism in Burmeisteria antarctica and hence Reed’s opinion may be correct. In any

case, the differences are not herein considered of specific importance and

Homalonotus hippocampus is included in the synonymy of B. herscheli.

Homalonotus lex Schwarz was founded upon several thoracic segments

(Fig. 17D) which Schwarz (1906: 389) felt might have belonged to the cephala

he had named H. hippocampus, while noting that ‘ . the rings show no

particular features differing from the usual H. herscheli type, except in the

ends, which in H. herscheli are rounded in the lower margin, in this species are

pointed, and probably bore spines’. The writer would agree with Reed (1925a)

that this is an unnecessary species that should be included in the synonymy of

B. herscheli.

Reed (1925a) created the var. rectisuturalis (Fig. 16E) within B. herscheli

for a cephalon ‘ ... which can hardly be separated specifically from H.

herscheli, but certainly constitutes a variety remarkable for the shortness and

breadth of its glabella’. The writer finds little use for this varietal name and it is

not used here.

The var. fusiformis was created by Reed (1925a) for the pygidium figured

by Lake (1904) (Fig. I1SA-B herein) and, as the varietal name implies,

distinguished by its subfusiform outline. While this variant is distinctive, no

further individuals have been forthcoming and the characters seem to be those

of an aberrant individual. As such, the perpetuation of Reed’s name is

tantamount to naming individuals and it is not used here.

Reed (1925a: 172) introduced the var. grahami (Fig. 21) for forms in which

the glabella was said to be more oblong in shape and relatively longer than in

typical B. herscheli, as well as having the cephalon more pointed anteriorly,

narrower, with steeper cheeks, and with‘... the meso-occipital furrow more

sharply bent forwards in the middle, the paraglabellar areas invade the basal

lobes more deeply, and the minute ornament is slightly different, the tubercles

being more numerous and closer together; the transverse suture is typically

straight and not angular’. Since, however, most of these characters are also

found in the ‘var. rectisuturalis’ and in ‘H. hippocampus’, this variety seems to

be based upon trivial differences of the individual and the name is not used

here.

Burmeisteria notica (Clarke) (1913: 89, pl. 1 (figs 1-2), pl. 2 (figs 1-13))

differs from B. herscheli in the complete lack of tubercles and spine bases to the

exoskeleton, a broader preglabellar field (about 25% of the sagittal length of

the cephalon) and a pygidium with fewer (13-15) axial rings. It is perhaps also

worthy of note that the pygidium figured by Clarke (1913) as plate 2, figures

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP Off

11-12 shows a distinctly deeper first ring furrow than the rest. Burmeisteria

clarkei (Kozlowski) and B. accraensis Saul are both very closely allied to B.

notica and distinguished from B. herscheli by the complete lack of tubercula-

ton.

Burmeisteria antarctica Saul (1965: 269, pl. 17 (figs 1-11)) (Fig. 29 herein)

differs from B. herscheli in its lack of tuberculation, shorter rostral suture,

allegedly smaller eyes and weaker glabellar segmentation, its relatively broader

cephalon, and particularly in features of the pygidium. Thus, in the “Type I’

pygidia (Fig. 29) of B. antarctica only the anterior 7-9 axial rings are distinct

and there are only 7 pairs of well-developed ribs to the pleural fields with very

deep interpleural furrows. The ‘Type II’ pygidia are closer to B. herscheli in

showing 12 or more axial rings, but still with only 6—7 pairs of pleural ribs.

Burmeisteria expansa (Hector) (Allan 1935: 29, pl. 1 (fig. 1)) from the

Reefton Beds of New Zealand is based upon pygidia which differ from B.

herscheli in being relatively much broader and with only 12-13 distinct axial

rings and 9-12 pairs of pleural ribs. Burmeisteria huttoni Allan (1935: 28, pl. 1

(figs 4-5)) is from the same beds and, in view of the range of variation

displayed by B. herscheli, probably does not warrant specific separation from

B. expansa. So far as can be judged, B. huttoni differs from B. herscheli in that

the coarse tuberculation of the thorax forms distinct transverse rows, whereas

in the South African species the rows tend to be longitudinal.

Occurrence

Burmeisteria herscheli (Murchison) is presently recorded from the Gydo,

Gamka, and Voorstehoek Formations of the Bokkeveld sequence, the Fox Bay

Beds of the Falkland Islands and, perhaps, from Bolivia.

Burmeisteria notica (Clarke, 1913)

Figs 14C, 30

Homalonotus noticus Clarke, 1913: 89, pl. 1 (figs 1-2), pl. 2 (figs 1-13).

Homalonotus cf. noticus Clarke, Kozlowski, 1923: 23, pl. 1 (fig. 11).

Homalonotus sp., Kozlowski, 1923: 13, pl. 3 (figs 8-9).

? Homalonotus (Burmeisteria) herscheli var. rectisuturalis Reed, 1925a: 160 (SU-—C1 only).

Homalonotus (Digonus) noticus var. africana Reed, 1925a: 184, pl. 10, (fig. 4).

Digonus noticus (Clarke) Sdzuy, 1957: 279.

Digonus cf. noticus (Clarke) Branisa, 1960: 60, pl. 6 (fig. 13); 1965: 84, pl. 10 (figs 5-7), pl. 11

(fig. 13), pl. 75 (fig. 2).

Burmeisteria (Digonus) noticus (Clarke) Saul, 1965: 271.

Burmeisteria (Digonus) cf. noticus (Clarke) Wolfart, 1968: 62.

Material

The holotype of Reed’s var. africana, SAM-7796, together with RO-17,

60, 88, 174, 297 and P57, and questionably SU-C1.

28 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 14. A-B, D-F. Burmeisteria herscheli (Murchison). A-B. SAM—PDB619, the original of

Lake (1904, pl. 26 (fig. 1)). D. SAM-—7201, with the lectotype of Deltacephalaspis pseudocon-

vexus (Lake) impressed in its terminal portion. E-F. SAM-PDB4345. C. Burmeisteria notica

(Clarke). SAM-—7796, the holotype of the var. africana Reed (1925a, pl. 10 (fig. 4)). A-B, D-F

preserved as internal moulds and all x 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 29

Fig. 15. Burmeisteria herscheli (Murchison). A-B. SAM-PDB627, the holotype of the var.

subfusiformis Reed, figured by Lake (1904, pl. 26 (fig. 2)). C. SAM-PDB4296.

D-E. SAM-PDB3075. F-G. SAM-PDB4353. All preserved as internal moulds and all x 1.

30 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 16. Burmeisteria herscheli (Murchison). A. SU-K810. B-C. A tectonically foreshortened

pygidium in the South African Museum. D. The original of Salter (1856, pl. 24 (fig. 7)), in the

British Museum. E. SU-C6, figured by Reed (1925a, pl. 10 (fig. 3)) as the var. rectisuturalis

Reed. All preserved as internal moulds and all x 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP Sil

Fig. 17. Burmeisteria herscheli (Murchison). A. SAM-7199, the holotype of the var. sodalis

Reed, figured by Reed (1925a, pl. 10 (fig. 5)), and preserved as an internal mould.

B-C. SAM-PDB600, the original of Lake (1904, pl. 26, (fig. 3)), which retains cuticle. D. The

lectotype, designated herein, of Homalonotus lex Schwarz, AM-1462, preserved as an internal

mould, showing the distal terminations of the thoracic pleurae. All x 1.

32 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 18. Burmeisteria herscheli (Murchison). A-B. SAM-PDB4356. C. SAM-PDB4293.

D. SAM-PDB4361, with a concave rostral suture. E. SAM-PDB4343. F. SAM-PDB4352.

G. An unnumbered cephalon in the South African Museum. All preserved as internal moulds

and all x 1.

33

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

‘Tx [[@ pue spjnow eussjur se poasasaid [TV ‘6serddd-WVS ‘O

‘p9EPAdd-WNVS “A ‘“wWhasny uROLyY YING oy) Ul UsUDads poroqunuUN uy “Vy

‘(UOSIYDIN,) Yayosiay visajsiauung

‘61 “S14

34

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 20. Burmeisteria herscheli (Murchison).

The holotype. by monotypy, of Homalonotus perarmatus Frech,

almost certainly an internal mould (after Frech 1897). x 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 35

Fig. 21. Burmeisteria herscheli (Murchison). AM-—2554, the original of Schwarz (1906, pl. 8

(fig. 8)), which was referred to the var. grahami Reed by Reed (1925a), preserved as an

internal mould. x 1.

Fig. 22. Burmeisteria herscheli (Murchison). A genal fragment in the collection of R. Oost-

huizen, showing the tubercles of the posterior border to represent spine bases, with some of the

spines bifurcating. Scale = 5 cm.

36 ANNALS OF THE SOUTH AFRICAN MUSEUM

GLABELLAR LENGTH 80mm

0

0 80mm

GLABELLAR WIDTH AT S1

Fig. 23. Burmeisteria herscheli (Murchison). Plot of glabellar length (sag.)

against glabellar width at the S1 sutures for the various rostral suture types.

Circles =concave rostral suture; triangles=straight rostral sutures;

dots = biconcave rostral sutures.

Discussion

This species is so similar to B. herscheli that it does not warrant additional

description on the basis of the available material. The small cephalon that

formed the basis of Reed’s var. africana (Fig. 14C) shows the lack of tubercula-

tion and relatively broad preglabellar field herein considered diagnostic of

Clarke’s species. It was assigned to B. notica by Reed (1925a: 185) ©... on

account of its proportions, the truncate and emarginate anterior margin, the

characters of the glabella, the course of the facial sutures, the well-rounded

genal angles, and especially in the absence of tubercles and spine bases. But

our specimen has a coarsely-granulated instead of smooth surface’. This latter

feature is surely an artefact of preservation, the Bokkeveld example retaining

cuticle, and hence Reed’s varietal name is not used here.

The small individual (Fig. 30) referred by Reed (1925a: 168) to B. her-

scheli var. rectisuturalis shows the lack of tuberculation typical of B. notica,

with the exception of a pair of spine bases on the posterior border just adaxial

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP oF

Fig. 24. Burmeisteria herscheli (Murchison).

Schematic representation of the cephalic tuberculation of various individuals.

Hatched areas not preserved.

38 ANNALS OF THE SOUTH AFRICAN MUSEUM

TS

Fi

nN

Pewee acs IMAL

eri

LUT TTT ETT PTTL 1)

Benes ant

SONA

ELUTE TT] = ALLER

\

AL

RRNNNSSSANAS

SO S

cca

Ns 2S Jay) 1

Schematic representation of the thoracic and pygidial tuberculation of

various individuals. Hatched areas not preserved.

(ess

is

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 39

Fig. 26. Burmeisteria herscheli (Murchison).

Schematic representation of the pygidial tuberculation of

various individuals. Hatched areas not preserved.

of the genal angles. The importance of this feature is uncertain, since this

individual also shows a pygidium with fewer axial rings (probably about 14)

than B. herscheli, and hence also approaches B. notica in this respect.

Burmeisteria clarkei (Kozlowski) (1923: 24, pl. 1 (figs 12-15)) is very close

to B. notica from which it was distinguished by the weaker trilobation and

segmentation of the pygidium, with a slightly different outline, and in

apparently having only 8 axial rings and 8 pairs of pleural ribs discernible. The

differences are slight and objective population analysis is required to confirm

the distinction of this species from B. notica.

Burmeisteria accraensis Saul (1967: 1129, pl. 143 (figs 1-8), pl. 144 (figs

1-16)) from the Devonian (Eifelian?) of Ghana was characterized by its lack of

tuberculation and lobation, and especially by having the first ring furrow of the

pygidium significantly deeper than the remainder. However, as noted by Saul

(1967: 1134) this latter feature is also found in at least some individuals of B.

clarkei while © ... the relative dimensions of H. clarkei, as measured from

Kozlowski’s plates, usually fall on the extreme peripheries of the scatter

diagrams which exhibit the range of variation of the Accraian species’. Kozlow-

ski’s species, however, was said to have a more acuminate pygidium. Since the

40

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 27. Burmeisteria herscheli var. quernus (Lake). A. SAM-626, the holotype of

this variety and original of Lake (1904, pl. 27 (fig. 1)). B. The pygidial fragment

figured by Lake (1904, pl. 27 (fig. 2)), in the South African Museum. Both preserved

as internal moulds and both x 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

Fig. 28. Burmeisteria herscheli var. quernus (Lake). A. SAM-2454, x 2. B. A speci-

men in the South African Museum, 1,5. Both preserved as internal moulds.

41

42

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 29. Burmeisteria antarctica Saul.

A. ‘Type I’ pygidium in lateral view

(after Saul 1965). x 1.

Fig. 30. Burmeisteria cf. notica (Clarke). SU-C1, a juvenile preserved

as an internal mould that may belong here. This specimen was referred

to Homalonotus herscheli var. rectisuturalis by Reed (1925a). x 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 43

population characteristics of B. clarkei are currently unknown, the differences

between the two species are slight and questionably of specific importance. Saul

(1967) failed to compare B. accraensis with B. notica. The lack of tuberculation

and glabellar segmentation are all features of B. notica and in relative propor-

tions the cephala of the two species are all but indistinguishable. Moreover, the

pygidium of B. notica figured by Clarke (1913, pl. 2 (figs 11-12)) shows the

same deep first ring furrow. Burmeisteria accraensis seems to differ from

B. notica only in its slightly shorter (sag.) preglabellar field and slightly nar-

rower pygidium, with all individuals apparently having the first ring furrow

deepened.

‘Homalonotus derbyi Clarke (1890: 7, pl. 1 (figs 4, 7, 19)) was said to be

. an excellent representative of the subdivision Trimerus’, while the lack of

segmentation to the pleural areas of the pygidium of ‘H’. kayseri Thomas

(1905: 245, pl. 11) suggests that it, too, may be a species of Trimerus.

Burmeisteria antarctica Saul was said to differ from B. notica in having a

straighter and shorter rostral suture, a more indented posterior margin to the

glabella, and a pygidium with deeper interpleural furrows becoming smooth

near the posterior termination, and with a sharper break at the connection of

ring furrows and rib furrows. Certainly “Type I’ pygidia are easily distinguished

from B. notica, but the “Type II’ pygidia, which Saul (1965) failed to compare

with B. notica, are very similar to Clarke’s species. Clearly, however, the

problem will be resolved only with the much-needed modern revision of

Clarke’s material.

Occurrence

Burmeisteria notica (Clarke) is currently recorded from Argentina, Bolivia,

and the Bokkeveld succession. The definitely localized specimen in the collec-

tion of R. Oosthuizen comes from the Gydo Formation.

Burmeisteria fontinalis (Reed, 1925)

Fig. 31

Homalonotus (Digonus) fontinalis Reed, 1925a: 185, pl. 10 (fig. 6).

Material

Only the holotype, SMC—A3069, from Ezelfontein is currently known.

Description

Cephalon. The anterior portion of the cephalon is indistinct in the photo-

graph of the holotype supplied by C. L. Forbes but, according to Reed

(1925a: 185), it has a ‘ ... truncate anterior edge, excavated in the middle’.

The glabella is weakly inflated, almost flat, and with indistinct lobation. It is

subrectangular in outline, narrowing slightly to the anterior. The glabellar

44 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 31. Burmeisteria fontinalis (Reed). The

holotype, by monotypy, SMC-A3069, pre-

sumably an internal mould. Note the lack of

tuberculation and numerous pleurae to the

pygidium. Approx. X 5.

furrows are all directed strongly posteromedially and all seem to be slightly

convex anteromedially. The occipital furrow is straight, narrow, of uniform

depth and distinctly narrower than the occipital ring. The posterior border

furrows are distinct and the posterior borders broaden (exsag.) abaxially. The

cheeks are poorly preserved but there appear to be weakly developed para-

glabellar areas, and the small eyes are raised on prominent bosses. The surface

of the cephalon is granulose but discrete tubercles are lacking.

Thorax. The thorax is poorly preserved, but with a wide axis, 13 segments

and a granulose surface.

Pygidium. The pygidium is strongly convex, subtrigonal in outline and with

well-developed trilobation. The axis is rather broad anteriorly and tapers

posteriorly into a bluntly rounded tip to leave a short post-axial field. The axis

comprises about 15 rings which are slightly wider than the ring furrows. The

pleural fields are subtrigonal and ornamented with 14-15 sharply raised, distinct

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 45

ribs which reach the pygidial margin and are said to be ornamented with coarse

granules.

Discussion

This species is most closely related to B. notica (Clarke) and its allies. It

differs from B. notica by its shorter preglabellar area, its relatively much longer

glabella, and especially in the characters of the pygidium, B. fontinalis having

many more pleural ribs than Clarke’s species. The above differences also serve

to distinguish B. fontinalis from B. clarkei (Kozlowski) and B. accraensis Saul.

Occurrence

Burmeisteria fontinalis (Reed) is known only by the holotype which comes

from an unknown level in the Bokkeveld sequence.

Superfamily DALMANITACEA Vogdes, 1890

Family Dalmanitidae Vogdes, 1890

Subfamily Dalmanitinae Vogdes, 1890

Genus Francovichia Brani§a & Vanék, 1973

Type species Odontochile branisi Wolfart, 1968;

by original designation

Francovichia clarkei (Ulrich, 1893)

Figs 32A, 33D, 34A, 35-36, 37A-B

Dalmanites clarkei Ulrich, 1893: 19, pl. 1 (fig. 13). Lake, 1906: 429. Knod, 1908: 500. Kozlow-

ski, 1923: 106. Swartz, 1925: 34.

Dalmanites lunatus Lake, 1904: 212, pl. 25 (fig. 6).

Dalmanites sp., Lake, 1904: 212, pl. 25 (fig. 7).

Non Dalmanites lunatus Lambert, 1904: 482, pl. 44 (figs 1-3, 5) (=D. limurulus (Green) fide

Delo, 1940).

Dalmanites (Hausmannia) dunni Reed, 1925a: 133, pl. 11 (fig. 5).

Dalmanites (Hausmannia) lunatus Lake, Reed, 1925a: 135.

Phacops sp., Brink, 1951: 162, figs 1-2.

Odontochile clarkei (Ulrich) Wolfart, 1968: 75.

Material

The holotypes of Dalmanites lunatus Lake, SAM-—66, and D. dunni Reed,

SAM-3949, together with RO-5, 51, 780, 783, PRV-—34-35, 623, and BPI-i113

and 1243.

Description

Cephalon. The cephalon is known, among South African material, largely

from the holotype of D. lunatus Lake (Fig. 35). This shows it to have been

semicircular, transversely much wider than long (sag.), and with prominent

genal spines extending backwards as far as the fourth thoracic segment. The

46

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 32. A. Francovichia clarkei (Ulrich). The holotype, by monotypy. of Dalmanites

(Hausmannia) dunni Reed (1925a, pl. 11 (fig. 5)). in the South African Museum,

SAM-3949, preserved as an external mould. B. Gen. et sp. indet. SAM-—784, the

original of Lake (1904, pl. 25 (fig. 5)), preserved as an internal mould. Both x 1,5.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 47

glabella expands anteriorly, with a much enlarged frontal lobe, but the anterior

region of the cephalon is too poorly preserved to be certain of the characters in

this region. The 3p furrows are fairly deep and directed strongly postero-

medially. The 2p and 1p furrows are moderately deep, transverse, and seem to

connect with the well-developed axial furrows. Both the L1 and L2 lobes are of

more or less constant width (exsag.). The occipital furrow is transverse, and the

smooth occipital ring seems to be broadest sagittally. The posterior border

furrows are deep and transverse, whereas the lateral border furrows are

shallow. The eye is very large, certainly 50 per cent of the exsaggital cephalic

length. A well-preserved eye that seems to belong to this species (Fig. 36)

comprises about 50 vertical files of lenses, with 15 ocelli in the central file and a

total of about 577 ocelli to the visual surface. It also shows an unornamented

palpebral lobe weakly separated from the unornamented palpebral area, as well

as a Shallow subocular groove separating the eye from the socle. The posterior

branch of the facial suture curves strongly forward before recurving to meet the

lateral border well in front of the posterior margin to the eye.

Thorax. The thorax comprises 11 segments, with a rather low, weakly

convex axis about one-third of the thoracic width. The ring furrows are very

much narrower than the axial rings themselves. The axis broadens (trans.) to

the third or fourth ring whereafter it tapers slowly to the posterior. The pleural

grooves are pronounced, with finer, narrower interpleural furrows.

Pygidium. Although the pygidium of D. lunatus is poorly preserved,

Dalmanites dunni is based upon adult topotype material (Fig. 32A) and,

together with additional topotype material, allows for a relatively comprehen-

sive description of the pygidium of this species.

The pygidium is large, triangular, distinctly wider (trans.) than long (sag.),

and with a long, narrow axis. The axis tapers regularly to the posterior, and

comprises 18-21 rings. After the tenth axial ring, the ring furrows become

obsolete sagittally. In none of the available material is the terminal portion of

the pygidium preserved, but in BPI-i243 (Fig. 37A-B) it is at least distinctly

mucronate; it is assumed to have had a terminal spine as in the South American

material. The pleural fields are broad, subtrigonal, strongly downturned at the

margins in well-preserved material, and with an entire border. There are 11

pairs of well-developed, flat-topped ribs, each bearing a very faint interpleural

furrow and separated by a deep, but narrow (exsag.) pleural groove, with a

very reduced and indistinct twelfth pair to the posterior. In the anterior

pleurae, the pleural grooves meet the axis almost at right angles, but the angle

becomes increasingly acute to the posterior, until the final few ribs are almost

parallel to the axis. The pleural segmentation is effaced distally to leave a

smooth narrow border. BPI-i243 retains granulose cuticle.

Discussion

Both Lake (1904) and Reed (1925a) remarked on the close similarity

between D. dunni and D. clarkei without effectively distinguishing them. The

48 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 33. A, C. Metacryphaeus caffer (Salter). A. SU-H76, the holotype of Eocorycephalus

capensis (Reed) (1925a, pl. 8 (fig. 5)). C. SU-C2, the holotype of Dalmanites (Proboloides)

ensifer Reed (1925a, pl. 8 (fig. 4)), which probably belongs to Salter’s species. Compare with

Figure 39F. x 1.5. B. Bainella africana (Salter). SU-K461. x1. D. Francovichia clarkei

(Ulrich). RO-5. x 1. E-F. Typhloniscus baini Salter. E. RO-702:; note the ‘eye ridges’. x 1.

F. RO-753, an individual retaining cuticle. X 2.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 49

Fig. 34. A. Francovichia clarkei (Ulrich). PRV—623, an external mould. x 1,3. B. Metacry-

phaeus caffer (Salter). PRV—1028, an internal mould showing a prominent auxiliary impres-

sion system. X 1,8.

50 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 35. Francovichia clarkei (Ulrich). Plasticine squeeze of the holotype of Dalmanites lunatus

Lake (1904, pl. 25 (fig. 6)), an external mould. Note the very large eyes. x 5.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 51

writer cannot find any significant characters to separate these two species, and

D. dunni is considered a junior subjective synonym of Francovichia clarket.

Dalmanites lunatus Lake is based upon an incomplete juvenile (Fig. 35)

that was collected from the same locality (Gamkapoort) as the holotype and

topotype material of D. dunni. As such, the two species seem to be based upon

different parts of different ontogenetic stages of the same animal and they are

herein regarded as conspecific. Dalmanites lunatus Lake is, therefore, included

in the synonymy of Ulrich’s species.

In the same year that Lake (1904) created his species, Lambert (1904) also

described a new species as Dalmanites lunatus from the Silurian of North

America. Since, according to Delo (1940: 44), D. lunatus Lambert (non Lake)

is a synonym of D. limurulus (Green), while Lake’s homonym is here included

in the synonymy of F. clarkei, this is a case for letting sleeping dogs lie and the

nomenclatural priorities of these two names are ignored.

Francovichia branisi (Wolfart) (1968: 72, pl. 6 (fig. 3), pl. 7 (figs 1-2)) is

very close to the present species. According to Wolfart (1968), there are 20-22

axial rings and 14 pairs of pleural ribs to the pygidium of F. branisi, which was

also said to have a somewhat narrower pygidium (with margins that are weakly

concave posteriorly) than F. clarkei. The differences in outline and width are

slight and may reflect merely intraspecific variation. Moreover, it is difficult to

determine more than 17 axial rings on the pygidium of F. branisi figured by

Wolfart (1968, pl. 6 (fig. 3)), or more than 12 pairs of pleural ribs. Franco-

vichia branisi does, however, seem to have smaller eyes and is for the present

retained as distinct.

‘Dalmanites’ andii Kozlowski (1923: 38, pl. 2 (figs 3-4)) differs from the

present species in having a much wider pygidium, and with prominent inter-

pleural furrows that are almost as wide as the ribs. These are also much the

same characters that distinguish ‘Dalmanites’ patacamayaensis Kozlowski

(1923: 36, pl. 2 (fig. 2)), Odontochile dunbari Delo (1940: 56, pl. 5 (fig. 7)) and

O. micrurus (Green) (Delo, 1940: 58, pl. 5 (figs 1-2)). The ‘Dalmanites’

maecurua Clarke figured by Knod (1908: 500, pl. 21 (fig. 3)) seems to have

fewer axial rings and wider interpleural grooves, which extend to the pygidial

margin, than the present species.

Occurrence

Francovichia clarkei (Ulrich) is currently known only from the Icla Forma-

tion of Bolivia and the Gydo Formation of the Bokkeveld sequence.

Family Synphoriidae Delo, 1935

Discussion

The evolution and phylogeny of this largely North American family has

been discussed at length by Lespérance & Bourque (1971, 1973) and Lespér-

ance (1975), and two subfamilies are currently recognized, the Synphoriinae

52 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 36. Franchovichia clarkei (Ulrich). BPI-i113. The large eye figured by Brink (1951,

figs 1-2), preserved as an internal mould. x 2,5.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 53

Fig. 37. A-B. Francovichia clarkei (Ulrich). BPI-i243, which seems to retain cuticle. x 2,4.

C-D. Bainella sp. nov. BPI-i244, a pygidium retaining cuticle. Note the weak tubercles on the

ribs at the pleural axis. x 2.

54 ANNALS OF THE SOUTH AFRICAN MUSEUM

and Trypaulitinae, with the origins of the family lying in ‘*... a generalized

Silurian Odontochile’ (Lespérance 1975: 99). Branigsa & Vanék (1973) intro-

duced three new genera from the Devonian of Bolivia that they believed should

be included here; these were Gamonedaspis, Fenestraspis, and Chacomurus.

However, only Chacomurus was accepted as a true representative of the

Synphoriidae by Lespérance (1975), who included it in the subfamily Trypauli-

tinae. Both Gamonedaspis and Fenestraspis were excluded because *... they

do not possess the characteristics of the family as now understood’ (Lespérance

1975: 101). It is perhaps significant, however, that Lespérance & Bourque

(1971) provisionally included Dalmanites accola Clarke in the Synphoriinae,

although Lespérance (1975: 103) later concluded that *... no compelling

evidence exists for [its] inclusion in the Synphoriidae’. Contrary to the opinion

of Lespérance (1975), however, Dalmanites boehmi Knod and the perhaps

conspecific D. accola Clarke are very close to certain Synphoriidae, especially

Roncellia and Anchiopsis. The Malvinokaffric species, on the face of it, seem to

be very closely related to Roncellia perceensis (Clarke) (Delo 1940: 59, pl. 5

(figs 5-6), pl. 6 (fig. 7); Lespérance & Bourque 1971: 190, pl. 26 (figs 1-3)),

the main points of difference being the relatively narrower pygidium with fewer

pleural ribs of the Malvinokaffric species. Since these differences are no greater

than those between many species of dalmanitid trilobites, one is left wondering

whether the Malvinokaffric species should not be included in the genus

Roncellia. However, Dalmanites boehmi and D. accola both differ from typical

Roncellia in having a median tubercle to the occipital spine, in which respect

they approach Anchiopsis. The pygidium of the latter genus is sufficiently

distinct, however, to preclude reference of the Malvinokaffric species to this

taxon.

The type species of Gamonedaspis, G. scutata Branisa & Vanék

(1973: 98, pl. 1 (fig. 6), pl. 4 (figs 1-2)), is known only from pygidia that show

the following features: longer than wide, subtrigonal in outline, and terminat-

ing in an uptilted postaxial spine. The axis tapers rather rapidly to the

posterior and comprises 13-14 rings, whereafter the segmentation becomes

indistinct. There are 9-10 pairs of pleural ribs, of which the anterior 3-4 show

faint pleural grooves. There are two longitudinal rows of tubercles on the axis

and randomly scattered tubercles on the pleural ribs. Thus, G. scutata differs

from Dalmanites boehmi and D. accola mainly in its uptilted post-axial spine.

On the basis of available evidence the differences are not herein considered of

generic importance and the writer would also refer D. boehmi Knod,

D. boehmi var. boliviensis Kozlowski, and D. accola to the genus

Gamonedaspis.

Whether the resemblances between Gamonedaspis and Roncellia are

another example of the perturbing homoeomorphy between boreal and

Malvinokaffric trilobites is at present uncertain. On the face of it, Roncellia,

Anchiopsis, Dalmanitoides, and Gamonedaspis show sufficient similarities to

Suggest they may form a third lineage within the Synphoriidae.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 5

Subfamily Synphoriinae Delo, 1935

Genus Gamonedaspis Brani§a & Vanék, 1973

Type species Gamonedaspis scutata Brani$a & Vanék, 1973;

by original designation

Gamonedaspis boehmi (Knod, 1908)

Figs 7A, 38, 39D, 40, 41A, 42C, 43, 44A

Dalmanites b6hmi Knod, 1908: 568, pl. 21 (fig. 1)

Dalmanites boehmi var. boliviensis Kozlowski, 1923: 36, pl. 2 (fig. 1). Swartz, 1925: 34.

Wolfart 1968: 70.

Dalmanites boehmi (Knod) Reed, 1925a: 133.

Francovichia? boehmi (Knod) Eldredge & Ormiston, 1979: 162.

Material

Thirteen specimens, SAM-—PDB3997, 4056, 4070, 4332, 4336, 4338-4339,

4348, 4358, RO-282, and PRV—34, 126, 1096, all preserved as internal moulds.

Description

Cephalon. The cephalon is semicircular in outline, about twice as wide as

the sagittal length, and weakly convex. The genal angles are not preserved in

the South African material but are assumed to be as in Knod’s (1908) figured

type. The axial furrows are strongly impressed and diverge markedly to the

anterior. There is a narrow preglabellar field that forms a bluntly rounded

median rostrum (Fig. 41A). The 3p furrows are rather deep, directed strongly

BR : RES

/

/

i

f Fig. 38. Gamonedaspis boehmi (Knod). \

Reconstruction of the cephalon based

upon the available material. x 1.

56 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 39. A-B. Bainella africana (Salter). SAM-PDB3076. x 2. C. Typhloniscus baini Salter.

RO-702a, a pygidium. x1.1. D. Gamonedaspis boehmi (Knod). SAM-PDB4338. X 2.

E. Burmeisteria herscheli (Murchison). An hypostoma, RO-279. x 1. F. Metacryphaeus caffer

(Salter). SAM-3960. x 2. All specimens preserved as internal moulds.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 57

posteromedially, and almost meet adaxially. They are weakly connected

proximally by a shallow transglabellar furrow that serves to isolate the pro-

minent, coarsely tuberculate, rhomboidal frontal lobe. The 2p and 1p fur-

rows are moderately deep, subparallel, with prominent adaxial apodemal

pits, and distinctly joined to the axial furrows. In large individuals

(Fig. 39D), the L3 lobes protrude laterally almost as much as the frontal

lobe, while the Ll lobes are very narrow (exsag.) and reduced. In

PRV-126a (Fig. 7A), the 3p and 2p furrows are joined proximally, so as to

isolate the L3 lobes, while the 2p and Ip furrows are also weakly joined,

tending to isolate the L2 lobes. Moreover, the 2p and 1p furrows are weakly

connected across the glabella (Fig. 43A) by variably developed transglabellar

furrows. The occipital furrow is rather narrow, with apodemal pits distally,

and separates the moderately broad occipital ring that bears a prominent

median tubercle (spine base?). The cheeks are subtrigonal in outline, mod-

erately downturned, with very deep posterior border furrows and posterior

borders which broaden (exsag.) abaxially. There are distinct palpebral fur-

rows that connect with the axial furrows anteriorly and, seemingly, with the

furrow separating the eye from its socle posteriorly. The cheeks lack tuber-

culation, although there are small tubercles on the palpebral lobes above the

eyes. The eyes are large, arcuate, about half the exsagittal length of the

cephalon, and separated from the L3 lobes anteriorly only by the axial

furrows. The visual surface comprises about 30-32 subvertical rows of ocelli,

with 8-9 lenses in the central files. The anterior ramus of the facial suture

touches, but does not transect, the lateral margin of the frontal lobe. The

posterior branch curves strongly forward before recurving sharply to meet

the lateral border in front of the posterior margin of the eye.

Thorax. Poorly known from South African material. So far as can be

ascertained there are no median tubercles to the axis nor any tubercles on the

pleurae. The axial furrows are moderately impressed, and there are deep

pleural grooves to the pleurae, which are separated by distinct interpleural

furrows. The distal terminations of the pleurae are unknown.

Pygidium. The pygidium is triangular, slightly wider than the sagittal

length (if the length of the post-axial spine is excluded), with gently convex

borders and a short terminal spine. The axis tapers uniformly to the posterior

and comprises between 15-18 rings, the segmentation becoming indistinct

posteriorly, each ornamented with a pair of tubercles close to the sagittal line.

The pleural fields are subtrigonal and separated from the axis by prominent

axial furrows. There are 11 pairs of rather broad, flat-topped ribs, the anterior

6-7 with faint pleural grooves. The interpleural furrows are deep and clearly

defined, and much narrower than the ribs. The pleural ribs meet the axis at an

acute angle (almost at right angles for the first few pleurae), which increases to

the posterior. A few randomly scattered tubercles of varying sizes ornament the

pleural fields, some situated directly upon the faint pleural grooves, and show a

tendency to mark the fulcral axis.

58 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fae inal .. ee

Fig. 40. Gamonedaspis boehmi (Knod). A. SAM-—PDB4339, a fragmentary cephalon.

B. SAM-PDB4332, a pygidium retaining the terminal spine. Both preserved as internal

moulds and both x 2.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 59

Fig. 41. A. Gamonedaspis boehmi (Knod). SAM-PDB4358. Note the

smooth anterior border and well-developed eye socle. x 1,5. B-C. Typhlo-

niscus baini (Salter). B. SAM-7799. The holotype of Acidaspis capensis

Reed (1925a, pl. 11 (fig. 6)). x 1,5. C. A specimen in the South African

Museum. Note the strong posterior taper of the thorax. x 1. All specimens

preserved as internal moulds

Discussion

Until the full range of intraspecific variation within G. boehmi is

documented, on the basis of a population of individuals, the largely trivial

characters on which Kozlowski (1923) separated his var. boliviensis are mean-

ingless and this taxon is not used here.

Gamondedaspis scutata Branisa & Vanék differs from the present species

in its uptilted post-axial spine, fewer (9-10) and narrower pleural ribs, and

ANNALS OF THE SOUTH AFRICAN MUSEUM

60

‘7 X [Je pue ‘spynow jeusojUI se poarosoid suautoads

IV “o49 oyi JO dovJINs [eNsIA oy} Surmoys ‘uoyeydao ay} JO MIIA [e1DIvT “(pouy) muya0q sidsppauowwyH ‘DJ ‘aqnuids yeuds ou

Jo uorssaidtut ay} SuIMoYs */pOPAdd-WVS ‘G “Winasnyy uespy YNOS ay) ul UoWOods y “g

"R]

[9qe[s Ss} JO Pole URIpoW payeyul

oy} Ul (YSH]) snxeauos “pw soyseosdde yey) yenpraipul ue “goopadd-WWS “WV ‘(4aues) 4affvo snavyd&uoviaw “Gq “q-V ‘Zp ‘Sly

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 61

seemingly fewer axial rings. It is also a somewhat older species. Gamonedaspis

accola (Clarke) (1913: 101, pl. 4 (figs 9-20)) is very close to the present species,

as noted by Kozlowski (1923). So far as can be judged from Clarke’s perhaps

somewhat idealized drawings, it differs from G. boehmi only in the irregular

development of the tubercles on the pygidial axis. Since this is perhaps an

artefact of preservation, G. accola is likely to become a synonym of Knod’s

species.

Occurrence

Gamonedaspis boehmi (Knod) is currently known with certainty only from

Bolivia and the Voorstehoek Formation of South Africa, but may also prove to

be present in Brazil.

Superfamily ACASTACEA

Discussion

On the basis of Eldredge’s (1979) phylogenetic analysis of this group of

trilobites, the writer is inclined to recognize the following subdivisions:

Family Acastidae

Subfamily Acastinae

Subfamily Acastavinae

Family Asteropygidae

Family Calmontidae

Subfamily Calmoniinae

Subfamily Bouleiinae

These taxa are united by the form of their auxiliary impression systems

which is *.. . a highly organized and distinctly triangular series of two major

radiating rows of impressions (with accessory impressions in subsidiary rows),

with the midline devoid of impressions, and with the widest portion of the field

situated adjacent to the pre-glabellar furrow or facial suture’ (Eldredge &

Branisa 1980: 191).

Family Calmoniidae Delo, 1935

Discussion

The quite remarkable pattern of speciation among the calmoniid trilobites

is undoubtedly due to adaptive radiation, causally related to marine transgres-

sion (Cooper 1977) and the niché diversity and abundance brought about by the

flooding of large areas of Gondwanaland by the late Emsian-early Eifelian

eustatic transgression. As such, there is likely to be a very high degree, if not

complete endemicity, of the taxa involved. Hence, the writer would agree with

Eldredge & Branisa (1980) in regarding the family as wholly Malvinokaffric.

ANNALS OF THE SOUTH AFRICAN MUSEUM

62

“Spynow [eusa}UI se paArosaid [[y ‘“¢‘] x

‘ogerpddd -NVS ‘Cd ‘S‘I x ‘sa]oroqny Jerxe posted oy) Surmoys */66€ AAd-WVS “A “91 x “Saqo] ET pur [eo

34} JO UONRIOSI puke SMOLIN Ie[JOqe|ssUeI] 9Y) NION ‘9SOPFAdd-WVS ‘O‘V ‘(pouy) muyaog sidsppauouwy ‘¢p “314

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 63

Such alleged calmoniids as Neocalmonia (Pillet 1969) are better assigned to the

family Asteropygidae, while Dalmaniturus is also excluded from the current

concept of the family.

Hupé (1955) created the monotypic subfamily Bouleiinae, within the

Phacopidae, for Bouleia but, as shown by Eldredge (1972), the latter genus is

merely a phacopid homoeomorph whose affinities are with the Calmoniidae. As

such, the Bouleiinae becomes a subfamily within the Calmoniidae. On hypo-

stomal characters and the strong reduction of the L1 lobes, the writer is also

inclined to place Parabouleia, Malvinella, and Vogesina in this subfamily.

Provisionally, therefore, the following taxa may be included in the sub-

family Calmoniinae: the Calmonia plexus comprising Calmonia, Paracalmonia,

Metacryphaeus (Metacryphaeus), M. (Wolfartaspis), Tibagya and Punillaspis,

the Phacopina plexus of Phacopina, Pennaia, Oosthuizenella and Andinacaste,

the Probolops group comprising Probolops, Tarijactinoides, Renniella, Cry-

phaeoides and perhaps Schizostylus, the unique Typhloniscus, and the group

comprising Bainella, Deltacephalaspis (Deltacephalaspis), D. (Prestalia), Koz-

lowskiaspis (Kozlowskiaspis) and K. (Romanops).

Genus Oosthuizenella gen. nov.

Type species Phacops ocellus Lake, 1904;

by original designation herein

Etymology

For Mr Roy Oosthuizen of Zwartskraal, Prince Albert, who allowed the

writer to study his magnificent collection of Bokkeveld trilobites, collected and

meticulously prepared over many years, and freely shared his expert knowledge

of this group.

Diagnosis

Cephalon subtrigonal in outline, wider than sagittal length. Genal angles

with small spiniform processes. 2p and 3p glabellar furrows subparallel and

characteristically sinuous and equally impressed; 2p furrows not reaching axial

furrows. 1p furrows very deep, concave anteriorly, and weakly connected to

axial furrows. Frontal lobe with pronounced ‘acastid’ auxiliary impression

system. Occipital furrow with strongly convex anterior margin and broadest

sagittally. Occipital ring smooth, of constant width. Eyes small (about one-third

of exsagittal length), situated between abaxial terminations of lp and 3p

furrows. Pygidium semicircular, broader than long, with 4 pairs of well-

developed pleural spines and a short post-axial spine. Axis rather broad,

comprising 8 rings of which the anterior 2 are most pronounced. Pleural fields

with 4, perhaps 5, pleurae with deep pleural grooves.

ANNALS OF THE SOUTH AFRICAN MUSEUM

64

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‘LO-OU “WUUY sisuapyuins vyjauing “DQ °8°7 x “pooy sypwuaiy (vuidosvyg) sdosvyg se ((Z] BY) 6 “1d ‘vSzI) pooy

Aq poinsy “¢6LL-WWS “(24"T) Snaingin vyauiwg “q “87x ‘PE-AUd ‘(pouy) Mya0q sidsypauowmy “Wy “pp “BIg

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 65

Discussion

Although Phacops ocellus Lake was originally included by Clarke (1913) in

his proposal of the genus Calmonia, the South African material shows certain

features that suggest generic separation. In all the South American species of

Calmonia the glabella shows transverse 2p furrows that deepen adaxially and

are more pronounced than the 3p furrows; there is an anterior border visible

dorsally and with a short median frontal process, and there are invariably 6

pairs of pleural spines to the pygidium. In Phacops ocellus, however, the 3p

and 2p furrows are equally developed, sinuous and parallel, without adaxial

deepening of the 2p furrows, the glabellar frontal lobe overhangs the anterior

border, there is no sign of a frontal process, and there are only 4 pairs of

pleural spines to the pygidium.

Oosthuizenella ocellus (Lake, 1904)

Figs 45-49, 50C, 85C

Calymene blumenbachii Murchison (non Brongniart), 1839: 654.

Phacops (Cryphaeus) africanus Salter, 1856: 218, pl. 25 (figs 6-7, 9 only).

Phacops ocellus Lake, 1904: 207, pl. 24 (figs 9-10).

Phacops (Cryphaeus) callitris Schwarz, 1906: 393, pl. 10 (fig. 2).

Pennaia africana Shand, 1914: 24, pl. 6 (figs 1-14). Swartz 1925: 51.

Phacops (Calmonia) ocellus Lake, Reed, 1925a: 153.

Phacops (Pennaia) africanoides Reed, 1925a: 158.

Phacops (Calmonia) callitris (Schwarz) Reed, 1925a: 149.

Acaste (Calmonia) callitris (Schwarz) Rennie, 1930: 344, pl. 9 (fig. 19).

Acaste (Calmonia) africana (Shand) Rennie, 1930: 344.

Bainella? ocellus (Lake) Struve (in Harrington et al.), 1959: 0484, fig. 383, 2f.

Calmonia ocellus (Lake) Eldredge & Ormiston, 1979: 158.

Calmonia? callitris (Schwarz) Eldredge & Ormiston, 1979: 158.

Material

The holotype, by monotypy, of Phacops ocellus Lake in the British

Museum, BM-In4957, together with the holotype of Pennaia africana Shand,

SU-E417B, the holotype and paratype of Phacops callitris Schwarz, AM-29

and AM-—34 respectively, AM-18 and RO-42, 777-778, E69, E94~-95, E42-45,

E61 and E66. All are preserved as internal moulds.

Description

Cephalon. The cephalon is subtrigonal in outline, convex, and about twice

as wide as the sagittal length. The glabella is moderately convex, pentagonal,

and with well-developed axial furrows diverging slightly to the anterior. There

are weak axial furrow pits. The frontal lobe is rhomboidal, with a pronounced

‘acastid’ auxiliary impression system, and overhangs the anterior border

slightly. The 3p and 2p furrows are equally impressed, parallel, distinctly

flexuous, and directed posteromedially. The 3p furrow does not reach the axial

furrow. Because the 2p furrows do not meet the axial furrows, the L3 and. L2

lobes are fused distally. The 1p furrows are anteriorly concave, with deep

apodemal pits, and connect weakly with the axial furrows. The occipital furrow

66

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 45. Oosthuizenella ocellus (Lake).

Reconstruction based upon the

available material. x 2.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 67

Fig. 46. Oosthuizenella ocellus (Lake). The holotype, BM-—In4957, figured by Salter (1856,

pl. 25 (fig. 6)) and Lake (1904, pl. 24 (fig. 9)). x 2.

is well developed with a strongly convex anterior border and an almost straight

posterior margin, and is thus broadest sagittally. There are deep apodemal pits

to the occipital furrow, immediately behind the L1 lobes. The posterior border

furrows are moderately deep, shallowing abaxially, while the lateral border

furrows are weakly developed and become obsolete anteriorly. The genal

angles are subrounded and bear short spiniform processes. The eyes are

relatively small about one-third of the exsagittal cephalic length, and situated

68 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 47. Oosthuizenella ocellus (Lake). RO-42, a somewhat crushed but relatively complete

internal mould. Note the prominent pygidial lappets and short terminal spine. X 3.

69

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

‘TT x Yjoqg puke spjnow yeusojul se poalosoid ylog “((Z “3Y) OT ‘Id ‘9061) zIeMYDS stamyjvI Sdoovyg

Jo adAjojoy 9y) *67-WV “G-d ‘Z1eMYoS siuyyjv9 sdoovyd Jo adAjered ay ‘po-WV ‘VW ‘(24eT) Snqjas0 vyauazmyisogQ ‘gp ‘S14

yp ay pL faa La a RCO a mamma aT reas tO

70 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 49. Oosthuizenella ocellus (Lake). RO-777. Posterior portion of thorax and anterior

portion of pygidium, showing the distinct pleural spines. Preserved as an internal mould.

x 2,8.

between the distal terminations of the 1p and 3p furrows. They comprise 23-24

vertical files, with 7-8 ocelli in the central files. The anterior branches of the

facial suture just transect the lateral extremities of the frontal lobe.

Thorax. The thorax is moderately convex, with an axis about one-third the

thoracic width. The axial rings are distally spatulate and separated by fairly

deep ring furrows with apodemal pits developed abaxially. The axial furrows

are moderately deep and distinct. The pleurae are convex, distally with short,

posteriorly directed spines, and with pronounced, anteriorly concave pleural

grooves that do not reach the distal extremities of the pleurae. The interpleural

furrows are moderately developed.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP TAL

Fig. 50. A-B. aff. Pennaia sp. AM-25, one of Schwarz’s (1906) syntypes of Phacops

gydowi. C. Oosthuizenella ocellus (Lake). SU-E417B, the holotype of Pennaia africana

Shand (1914, pl. 6 (figs 1-4)), renamed Phacops (Pennaia) africanoides Reed (1925a).

D. Pennaia? sp. AM-—26, selected by Schwarz (1906) as the type for the body of

Phacops gydowi Schwarz. E. Typhloniscus baini Salter. SU-K463. F. Bainella africana

(Salter). RO-784. All preserved as internal moulds and all x 1.

Pygidium. The pygidium is subtrigonal in outline, almost semicircular,

convex, and with a pronounced axis. The latter comprises 8 rings, of which only

the anterior 2 are separated by well-developed ring furrows. The axis tapers

posteriorly for the first 3 rings, after which the axial furrows become subparal-

lel, and is bluntly rounded posteriorly. The pleural fields are gently convex and

comprise 4, perhaps 5, pleurae, each with deep pleural grooves and faint

interpleural furrows. The pleurae terminate in well-developed, short, pos-

teriorly directed spines of which there are 4 on either margin. There is a short,

pointed post-axial spine.

2 ANNALS OF THE SOUTH AFRICAN MUSEUM

Discussion

This species differs from all described species of Calmonia in features of —

the glabellar segmentation and in possessing only 4 pairs of pleural spines to

the pygidium. It is also close to Pennaia pupillus (Lake) but the latter species

lacks spiniform processes to the genal angles, has transverse 2p glabellar

furrows which deepen adaxially, possesses fewer axial rings and pleurae to the

pygidium, with only 3 pairs of minute pleural spines, and lacks a terminal

spine.

The material assigned by Clarke (1913, pl. 5 (figs 10-15)) to this species

differs in possessing deep, transverse 2p furrows and at least 5 pairs of pleural

spines to the pygidium. According to N. Eldredge (in litt. 1980), this material is

assignable to Oosthuizenella.

Occurrence

Oosthuizenella ocellus (Lake) is currently known with certainty only from

the Gydo Formation, but may be present in the Falkland Islands.

Genus Pennaia Clarke, 1913

Type species Pennaia pauliana Clarke, 1913;

by original designation

Discussion

Eldredge & BraniSa (1980) have recently discussed the Malvinokaffric

species of Acastoides, noting that they differ from the Boreal species (which

include the type of the genus) in having (i) shorter and narrower pygidia, (ii) a

prominent axis, bluntly rounded posteriorly and with a distinct post-axial field,

(111) a less well-differentiated palpebral complex, and (iv) the posterior borders

of the cephalon strongly convex so that the genal angles are situated opposite

the posterior margins of the eyes. Moreover, they noted, as had Kozlowski

(1923), that in well-preserved material there were small lappets to the anterior

three pleurae of the pygidium. In the latter character, ‘Acastoides’ verneuili

(d’Orbigny) is obviously allied to Pennaia and was, in fact, assigned to this

genus by Reed (1927). It is highly significant, therefore, that the Bolivian

‘Acastoides’ species differ from the type species of Acastoides in having well-

developed L1 lobes to the glabella and a hypostoma with the maculae situated

on the anterior margin of the middle body, not laterally as in A. henni

(Richter). In consequence, the Bolivian “Acastoides’ species are here transfer-

red to Pennaia although the strongly convex posterior border of P. verneuili

(d’Orbigny), with the concomitant shift in position of the genal angles, the

pronounced auxiliary impression system and the anteriorly convex form of the

2p glabellar furrows, may prove to warrant subgeneric separation. As such,

Pennaia should be regarded as a synchronic Malvinokaffric homoeomorph of

the Boreal Acastoides.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP Ws

Pennaia pupillus (Lake, 1904)

Figs 6C, 51-55, 56C—G, 58E-F, 59C-D, 99D

Phacops pupillus Lake, 1904: 203, pl. 24 (fig. 1).

Phacops impressus Lake, 1904: 209, pl. 25 (fig. 1).

Phacops (Cryphaeus) gydowi Schwarz, 1906: 396, pl. 10 (fig. 3).

Phacops (Calmonia) impressus Lake, Reed, 1925a: 150.

Phacops (Calmonia) impressus var. vicina Reed, 1925a: 151, pl. 11 (fig. 8).

Phacops (Calmonia?) pupillus Lake, Reed, 1925a: 156.

Phacops (Pennaia) gydowi Schwarz, Reed, 1925a: 157, pl. 9 (fig. 7), pl. 11 (fig. 2).

Acaste (Pennaia) impressus (Lake) Rennie, 1930: 338, pl. 9 (figs 5-13).

Metacryphaeus ? pupillus (Lake) Eldredge & Ormiston, 1979: 160.

? Phacops (Cryphaeus) africanus Salter, 1856: 218, pl.25 (figs 2, 9c, 10, 13 only).

Material

The holotype, by monotypy, SAM-K60, together with SAM-1167, 2463,

7187, 8959, 8961, 8963, 8966-8967, 8969, 9605, PDB3078, PRV-37, 3200,

AM-26, 28, 69, KM-418, BM-—52061, 1In28613-28614, 28616, 28618-28619,

IM29236, and RO-4, 213, 273, 704, 758, 762, 774, 781, 791, 797, 831, C70,

E26, 28, 78-79, L76, and P2.

Description

Cephalon. The cephalon is rather convex, subtrigonal in outline and

about twice as wide (trans.) as the sagittal length. The glabella is moderately

convex, subpentagonal, widening slightly to the anterior and typically with a

thomboidal frontal lobe. The auxiliary impression system is poorly developed

and only occasionally visible, e.g. PRV-3200. The axial furrows are well

defined, subparallel, and with prominent axial furrow pits opposite the distal

terminations of the 3p furrows. The latter are moderately impressed, straight

to very slightly sinuous, and distinctly connected to the axial furrows. The 2p

furrows are deep, transverse, and distally obsolete, so that L2 and L3 coalesce

distally. The 1p furrows are very deep, directed slightly posteromedially, and

distinctly connected to the axial furrows. There is a slight forward curvature

of the adaxial ends of the 1p furrows as well as a weak, but distinct adaxial

bifurcation well seen in the lectotype. The L1 lobes broaden abaxially. The

cheeks are subtrigonal, moderately convex and down-turned and apparently

lacking spiniform processes. The posterior border furrows are deep, trans-

verse, becoming shallower distally, whereas the lateral border furrows are

shallow and poorly defined. The anterior border is very narrow, and generally

obscured dorsally by the frontal lobe. The occipital furrow is rather deep,

anteriorly convex, widest sagittally, and with deep apodemal pits distally. The

smooth occipital ring is of more or less constant width, and the posterior

borders broaden (exsag.) slightly towards the genal angles which are sub-

rounded. The eyes are rather large, somewhat more tha one-third of the

exsagittal cephalic length. The visual surface comprises 28-29 vertical rows of

ocelli, with 7-8 lenses in the middle row. The anterior branch of the facial

suture only just transects the lateral extremities of the frontal lobe (fig. 54),

74 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 51. Pennaia pupillus (Lake).

A reconstruction based upon

the available material. x 2.

while the posterior branches meet the lateral margins more or less in line with

posterior ends of the eyes.

Thorax. The thorax is strongly convex, with an axis about one-third of the

thoracic width. The axial rings are distally spatulate and separated by rather

deep intersegmental grooves that bear apodemal pits distally. The pleurae are

convex, with deep, anteriorly concave pleural grooves that taper distally and

become obsolete before reaching the distal extremities of the pleurae. The

latter are ornamented with minute, posteriorly directed spines.

Pygidium. The pygidium is semicircular to subtrigonal in outline, mod-

erately convex, and with an axis composed of 8-f0 rings. The axis tapers

uniformly to the posterior and there is no post-axial field. The pleural fields are

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 1D

gently convex and comprise 5, possibly 6, pairs of pleurae, each with deep,

well-defined pleural grooves that become obsolete before reaching the pygidial

border. Distinct interpleural furrows are developed only between the anterior

pleurae; posteriorly they are only faintly visible mesially. Like the pleural

grooves, the interpleural furrows are distally obsolete, so the pygidium is left

with a smooth border. The pygidial margin is ornamented with 3 (? occasionally

4, fide Rennie 1930) pairs of very short, broad, triangular spines that are

directed posteriorly and correspond with the anterior 3 pleurae. Behind these

spines the pygidial margin is entire.

Discussion

Lake (1904) considered the holotype of Phacops pupillus to have spiniform

processes to the genal angles but, as can clearly be seen from Figure 52, this is

an artefact of preservation. The posterior border of the left cheek of the

holotype has been broken off for almost its entire length, save for a small,

narrow remnant at the genal angle; this gives the erroneous impression of a

spiniform process to the genal angle.

In creating Phacops impressus, Lake (1904: 209) noted that ‘.. . this form

is represented by several nearly complete specimens, but they are so much

crushed and distorted that it is impossible to determine accurately the charac-

ters of the head’. Since then, however, Rennie (1930) has provided an excellent

description of this species, based upon well-preserved topotype material, and it

is now clear that P. pupillus and P. impressus were originally based upon

different parts of the same animal. Unfortunately, because of page priority, the

better known Pennaia impressus (Lake) must become a junior subjective

synonym of P. pupillus.

A perturbing feature of the Pennaia material from the Bokkeveld succes-

sion is that few examples have identical cephala (Fig. 59), but seemingly all

have identical thoraxes and pygidia. On the basis of current taxonomic practice

within the group, a number of these could perhaps be given new specific names.

However, the writer is not yet certain that more than a single, highly variable,

polytypic species is present. Thus, PRV-—3100 (Fig. 58E-F) differs from typical

P. pupillus in having the posterior borders arched strongly forward so that the

genal angles, which are acuminate, are situated opposite the posterior portions

of the eyes. This specimen also has relatively somewhat smaller eyes than

typical P. pupillus, and with a broader frontal lobe. The glabellar segmentation

is also somewhat more deeply impressed and the 2p furrows are not quite

transverse. It thus approaches an unnumbered specimen in the South African

Museum (Fig. 99D) that differs in having transverse 2p furrows and a relatively

broader (trans.), almost elliptical frontal lobe. The latter example approaches a

specimen in the British Museum (Fig. 62B) that shows a similar frontal lobe,

but now with a distinct auxiliary impression system and similar 2p furrows, but

this specimen now has a transverse posterior border, thus resembling typical P.

pupillus. From the latter it differs, however, in having a relatively broader,

76

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 52. Pennaia pupillus (Lake). The holotype, by monotypy, SAM—PDB60, which

retains cuticle. Note the pseudo-spiniform process formed by the destruction of the

posterior border, the distinct posterior branch to the lp furrow, and the strong

homoeomorphic resemblance to Phacopidina in lateral view. X 4.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP Wa

A

Thi

|

} be =

Fig. 53. Pennaia pupillus (Lake). SAM-1167, figured by Reed (1925a, pl. 9 (fig 7)), and

preserved as an internal mould. x 2.

ellipsoidal frontal lobe with a distinct auxiliary impression system and Ip

furrows that do not show adaxial bifurcation. Phacopina lakei (Reed) differs

from Pennaia pupillus in its very much broader (trans.), elliptical frontal lobe,

with the anterior border distinctly visible in dorsal view. It also has less deeply

impressed 2p and 3p furrows, 2p furrows that are anteriorly convex, narrower

L1 lobes, and posterior borders that curve weakly forward (Fig. 59A). Until

very much bigger collections are available for study, the writer prefers to

subscribe most of the above differences to intraspecific and ontogenetic varia-

tion. This tends to be supported by their sympatric association and the fact that

only one type of thorax and pygidium can, at present, be identified.

Pennaia pauliana Clarke (1913: 133, pl. 5 (figs 18—25)) is very similar to the

present species but was said to have only 3-4 well-defined axial rings to the

pygidium, whereas in P. pupillus there are 8-10. Furthermore, the pleural

grooves of the thorax of P. pauliana are not anteriorly concave as in the South

African species. Although the differences are slight, the author prefers to

maintain P. pauliana as distinct until it is revised on the basis of type and

topotype material.

78

Fig.

the

ANNALS OF THE SOUTH AFRICAN MUSEUM

54. Pennaia pupillus (Lake). SAM-—8969a, preserved as an internal mould. Note how

anterior ramus of the facial suture transects the extreme lateral margin of the frontal

lobe. X 4,1.

Fig.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

55. Pennaia cf. pupillus (Lake). SAM-8961, preserved as an internal mould.

Note the oval shape to the frontal lobe. x 4.

79

80

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 56. A-B. Metacryphaeus caffer (Salter). A. SAM-—PDB4345. x 1,5. Note

the length and shape of the pleural lappets to the pygidium. B. SAM-—PDB7787.

x1. C-G. Pennaia pupillus (Lake). C-D. SAM-—PDB3078. x 1. E-F. AM-28,

the holotype of Phacops gydowi Schwarz (1906, pl. 10 (fig. 3)). x1.

G. KM-418, the original of Reed (1925a, pl. 11 (fig. 8)). x 1. H. Burmeisteria

herscheli (Murchison). A specimen in the South African Museum retaining spines

to the thoracic axial ring. X 2. All specimens preserved as internal moulds.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 81

Fig. 57. A. Bainella africana (Salter). SAM-PDB3080, the internal mould of an hypostoma.

x4. B. Pennaia sp. SAM-11915, the posterior portion of the thorax and terminally eroded

pygidium, preserved as an internal mould. x 4.

82 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 58. A-D. Bainella africana (Salter). A. RO-30. x2. B-—C. SAM-—782, the original of

Lake (1904, pl. 24 (fig. 6)). x 2. D. SAM-PDB3945. x 2. E-F. Pennaia aff. pupillus (Lake).

PRV-3100. Note the strongly curved posterior border and acuminate genal angles. X 2,7.

‘€ x “xoidde ]je pue spnow jeurdjur

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a JO [eursi1o ay ‘ds gvuidoopyg *g ‘(paay) 12yn] vundosvyg “Ww ‘eyeydao puidospyd pure vivuuag pojon14su0de1 uIOS JO uostiedulog ‘6S “314

oe)

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

RW

84 ANNALS OF THE SOUTH AFRICAN MUSEUM

‘Acastoides’ koukharskii Baldis & Longobucco (1977b: 171, figs 1-3) is

neither an Acastoides nor a Pennaia. It differs from both these genera in having

2p furrows that connect with the axial furrows and L2 lobes that narrow

(exsag.) abaxially.

Pennaia gamonedensis (Eldredge & BraniSa) (1980: 237, fig. 19) differs

from P. pupillus in having smaller eyes, lightly impressed 2p and 3p furrows,

the latter almost transverse, and with a pygidium with only 2 distinct axial rings

and 4 pleural grooves.

Occurrence

Pennaia pupillus (Lake) is known with certainty only from the Gydo

Formation, although there is a single pygidium, PRV-39, in green shale

preservation that may be from the Voorstehoek Formation.

Genus Metacryphaeus Reed, 1907

Subgenus Metacryphaeus Reed, 1907

Type species Phacops caffer Salter, 1856;

by the subsequent designation of Rennie, 1930

Discussion

Wolfart (1968) recognized two species groups within Metacryphaeus; the

group of M. caffer was said to comprise M. caffer (Salter), M. australis

(Clarke), M. praecursor Wolfart, and M. venustus Wolfart, and characterized

by a comparatively small exoskeleton, relatively large eyes and a limited

capacity for spine formation. The group of M. giganteus was said to comprise

M. giganteus (Ulrich), M. convexus (Ulrich), M. dereimsi (Groth), M. boulei

(Kozlowski), M. cornutus Wolfart, and M. tuberculatus Kozlowski, and typified

by the relatively larger size of the exoskeleton, relatively smaller eyes, and a

marked capacity for spine formation.

The writer finds this division of little practical use since M. tuberculatus is

a probable synonym of M. caffer, while M. caffer is very closely related to,

and probably descended from M. giganteus, as well as being of a comparable

size. It is pertinent to note, however, that Eldredge & BraniSa (1980) report

the presence of two distinct types of hypostomata among Metacryphaeus

species.

Among the large number of Metacryphaeus species now known, one

species stands alone. This is M. cornutus Wolfart (1968: 95, pl. 12 (figs 2-5), pl.

13 (figs 1-4), pl. 14 (figs 1-2) (Fig. 60 herein), which can be distinguished from

all other described species of Metacryphaeus in the possession of a cylindrical

terminal spine to the pygidium and a thick, cylindrical median spine to the

occipital ring. It is accordingly made the type species of the new subgenus

M. (Wolfartaspis).

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 85

Fig. 60. Metacryphaeus (Wolfartaspis) cornutus Wolfatt.

A reconstruction based upon the figured material. Approx. x 1,5.

Metacryphaeus (Metacryphaeus) caffer (Salter, 1856)

Figs 6D, 33A, C, 34B, 39F, 42A-B, D, 44D,

56A-B, 61, 62A, 63-64, 65C-D, 66A, 67A,

68B, 69-70, 78D, 98A, C, 99C

Phacops caffer Salter, 1856: 219, pl. 25 (figs 11-12 only).

Phacops (Cryphaeus) africanus Salter, 1856: 218, pl. 25 (fig. 4 only).

Phacops (Cryphaeus) caffer Salter, Lake, 1904: 210, pl. 25 (figs 3-4). Schwarz, 1906: 395.

Clarke, 1913: 72.

Dalmanites (Cryphaeus) caffer (Salter) Reed, 1925a: 139, pl. 9 (figs 10-11), pl. 11 (fig. 4).

Dalmanites (Cryphaeus) caffer var. albana Reed, 1925a: 144, pl. 11 (fig. 1).

Dalmanites (Cryphaeus) cf. australis (Clarke) Reed, 1925a: 146, pl. 11 (fig. 9).

86 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dalmanites (Cryphaeus) cf. pentlandi (Salter) Reed, 1925a: 146, pl. 11 (fig. 10).

Dalmanites (Cryphaeus) caffer (Salter) var., Reed, 1925a: 145.

Dalmanites (Corycephalus ?) capensis Reed, 1925a: 131, pl. 8 (figs 5-6).

Dalmanites (Eocorycephalus) capensis Reed, 1925b: 133.

Asteropyge caffer (Salter) Reed, 1927: 310.

Dalmanites (Metacryphaeus) caffer (Salter) Rennie, 1930: 336, pl. 9 (figs 3-4).

Metacryphaeus caffer (Salter) Reed, 1907: 168. Struve (in Harrington et al.), 1959: 0484, fig.

383, 3c. Wolfart, 1968: 81. Eldredge & Ormiston, 1979: 159.

? Dalmanites (Cryphaeus ?) cf. rostratus Kozlowski, Reed, 1925a: 147, pl. 8 (fig. 2).

? Dalmanites (Proboloides) ensifer Reed, 1925a: 136, pl. 8 (fig. 4).

? Schizostylus ensifer (Reed) Wolfart, 1968: 113.

? Schizostylus (Curuyella) ensifer (Reed) Eldredge & Ormiston, 1979: 159. Eldredge & Brani§a,

1980: 228.

Fig. 61. Metacryphaeus (Metacyphaeus) caffer (Salter).

A reconstruction based upon the available material.

Approx. X 1,5.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 87

Material

Numerous specimens including the lectotype, BM—In28620 (Fig. 62A), and

BM-28783, BM-Itl1619, ?SMC-A3063, SAM-PDB2463, 3088, 3850, 3943,

4000, 4041, 4047, 4068, 4075, 4078, 4329, 4335, 4340-4341, 4346-4347,

4350-4352, 4354, 4363, 7184-7185, 7788-7790, 7792, 7799, 11900, PRV-5, 922,

1028, 1070, AM-74, SU-C2, 13, SU-H73, 76, 172-3, SU-E414, 483, together

with RO-68, 207, 241, 285, 703, 820-828, 833, E60, 77, 93, and 96.

Description

Cephalon. The cephalon is moderately convex, semicircular to semi-

elliptical in outline, and more than twice as wide as the sagittal length. The

glabella expands evenly towards the anterior with deep, straight axial furrows.

The inflated frontal lobe is coarsely pitted by internal muscle scars, and there

is a well-developed posterior median impression. The 3p furrows are strongly

developed, directed posteromedially at about 60° to the axial furrows and

distinctly connected to the latter. The 2p furrows are transverse, deepest

adaxially, and only very weakly connected to the axial furrows. The 1p

furrows are normal to the axial furrows and thus directed slightly anterome-

dially, with the result that the L1 lobes tend to have a uniform width (exsag.).

They have deep apodemal pits adaxially and are slightly more strongly con-

nected to the axial furrows than the 2p furrows. The occipital furrow is rather

deep, with abaxial apodemal pits, and a moderately convex anterior margin

but an almost transverse posterior border, with the result that it is broadest

sagittally. The occipital ring is of uniform width, straight, transverse, and

wider (sag.) than the occipital furrow. The posterior border furrows are rather

broad (exsag.) and deep, and meet the moderately developed lateral border

furrows in acute angles at the genal angles which bear short spiniform

processes. The anterior border furrow is very shallow and weakly developed

but there is a short but distinct uptilted median frontal process. The cheeks

are subtrigonal in outline and moderately convex. The eyes are moderately

large, about one-third of the exsagittal length, and comprise 23-27 vertical

files of lenses, with 8-9 lenses in the central file. The eyes are strongly

arcuate, with distinct palpebral furrows, and touch the axial furrows anteriorly

immediately behind the abaxial terminations of the 3p furrows. The posterior

borders of the eyes lie in a plane slightly anterior to the distal terminations of

the 1p furrows.

Thorax. The thorax is moderately convex, with an axis about one-third the

thoracic width. The axial rings are distally spatulate and separated by mod-

erately wide, deep, ring furrows with abaxial apodemal pits. The axial furrows

are deep and well defined. The pleural fields are moderately convex, with

pronounced fulcra at about the middle of their transverse widths. The promi-

nent deep pleural grooves are almost straight, tapering distally and becoming

obsolete before the abaxial terminations of the pleurae are reached. The latter

88 ANNALS OF THE SOUTH AFRICAN MUSEUM

bear small, posteriorly directed spines. The interpleural furrows are well

developed, narrower than the pleural grooves, deepest adaxially, and show

distinct geniculations at the fulcra.

Pygidium. The pygidium is almost semicircular in outline, distinctly

wider than the sagittal length, and moderately convex. The axis is broad

anteriorly and tapers rather rapidly to the posterior for the anterior 5 rings,

whereafter the moderately deep axial furrows become subparallel. There are

about 10 axial rings, of which the last few are rather indistinct, separated by

rather broad (sag.) ring furrows. The anterior 34 rings retain spatulate

distal terminations, while the anterior 4-5 ring furrows have prominent

apodemal pits distally. The axis terminates in a bluntly rounded tip inside

the pygidial margin so as to leave a short but distinct post-axial field. The

pleural fields are subtrigonal, gently convex, each comprising 5 distinct pleu-

rae that extend beyond the pygidial border to form prominent posteriorly

directed lappets. The pleural grooves are broad and rather deep, tapering

abaxially to become obsolete before the distal terminations of the pleurae

are reached. The interpleural grooves are fine, tending to broaden and

become more pronounced distally. There is an incompletely developed sixth

pair of pleurae which does not develop lappets. The posterior margin of the

pygidium is evenly rounded to slightly pointed between the fifth pair of

lappets and is arched sagittally.

Discussion

In the interpretation of this species, and all the material discussed herein,

the writer has been strongly governed by the consideration that a species is

typified by the statistics of a population of individuals, not solely the characters

of the holotype. Consequently, many of the trivial differences of previous

workers are not herein considered of specific importance.

As noted by Rennie (1930), Dalmanites (Eocorycephalus) capensis (Fig.

33A) Reed was based upon damaged cephala of Metacryphaeus caffer of which

it is, therefore, a synonym. Both Reed’s (1925a) var. albana, said to have a

more subquadrate glabella and to lack a median frontal process, and his

Dalmanites (Cryphaeus) caffer var., based upon a pygidium distinguished by

the more rapidly tapering axis and broader (sag.) post-axial field, are based

upon characters of the individual that are not herein considered of taxonomic

importance.

Dalmanites (Proboloides) ensifer Reed (Figs 33C, 64H) was based upon a

unique cephalon that subsequently has generally been assigned to the genus

Schizostylus. The writer has had the opportunity of studying this specimen;

there seems little justification for interpreting the median frontal process as

long as did Reed (1925a), and this is certainly a species of Metacryphaeus. It

differs from M. caffer mainly in its state of preservation: it represents nodule

preservation whereas most of the M. caffer material is preserved as dorsoven-

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 89

trally compressed internal moulds. It is only because of the different modes of

preservation, reflecting perhaps different stratigraphic levels, that the writer is

somewhat hesitant unequivocally to include Dalmanites ensifer in the synonymy

of Salter’s species.

The Dalmanites (Cryphaeus) cf. rostratus Kozlowski figured by Reed

(1925a) (Fig. 70 herein) would appear to represent nothing more than a

well-preserved frontal process such as might have been found on the holotype

of D. (Proboloides) ensifer. Perhaps significantly, however, it is associated with

Bainella and hence may represent a lower stratigraphic horizon than typical

M. caffer. The true Dalmanites rostratus Kozlowski (1923: 44, pl. 5 (figs 1-9)) is

the type species of the genus Cryphaeoides Delo (1935) and bears only a very

superficial resemblance to M. caffer.

Dalmanites (Cryphaeus) cf. pentlandi Salter (Reed 1925a, pl. 11 (fig. 10))

(Fig. 67A herein) was said to differ from M. caffer in being rather coarsely and

irregularly tuberculate. It seems probable, on account of the large size of this

individual (sagittal length 71 mm excluding the cephalon), that the slight

differences are due to a comparison of different ontogenetic stages.

Reed’s (1925a: 145, pl. 11 (fig. 9)) Dalmanites (Cryphaeus) cf. australis

Clarke was distinguished from M. caffer by its smaller eyes placed further to

the anterior, its less inflated glabella and its more pointed genal angles. The

writer has studies this specimen and is of the opinion that it is an individual of

M. caffer. However, M. australis (Clarke) (1913: 110, pl. 4 (figs 1-5)) is indeed

very close to M. caffer and, to judge from Clarke’s perhaps idealized drawings,

differs mainly in its relatively larger cheeks and the shape of the genal angles. It

is noteworthy, however, that Clarke (1913: 114) wrote ‘ ... the writer finds

figure 4 of Salter’s Cryphaeus africanus a true Cryphaeus tail and identical with

C. australis; he believes that Salter’s figure 1 belonged to the same animal and

is Cryphaeus australis... . While the Phacops africanus rests well enough on

Mr. Lake’s type, let it be understood that Cryphaeus australis is present in the

Bokkeveld fauna.’ Clearly the taxonomic status of M. australis must await the

modern revision of Clarke’s material.

Metacryphaeus boulei (Kozlowski) (1923: 46, pl. 2 (fig. 15); Wolfart

1968: 88, pl. 11 (figs 1-3)) is a coarsely tuberculate species bearing a homoeo-

morphic resemblance to Bainella arbuteus (Lake), which is easily distinguished

from M. caffer. M. cornutus Wolfart (1968: 95, pl. 12 (figs 2-5), pl. 13 (figs

1-4), pl. 14 (figs 1-2)) is readily separable from M. caffer in the possession of a

long, cylindrical median spine to the occipital ring and a terminal spine to the

pygidium.

Metacryphaeus venustus Wolfart (1968: 99, pl. 15 (figs 2-4), pl. 16, pl. 17

(figs 1-6)) is very close to M. caffer and perhaps especially to M. australis. It

seems to differ from the South African species in its relatively longer (sag.)

cephalon, with more strongly diverging axial furrows to the glabella, and its

somewhat larger eyes that are not quite as close to the axial furrows as in

M. caffer.

90

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 62. A. Metacryphaeus caffer (Salter). The lectotype, BM—In28620, figured by

Salter (1856, pl. 25 (fig. 11)). x 1,5. B. Phacopina? sp. BM-In28619, the orig-

inal of Salter (1856, pl. 25 (fig. 10)), tentatively referred to Phacopina lakei

(Reed) by Reed (1925a). Note the oval frontal lobe, distinct auxiliary impression

system and relatively large eyes. X 3. Both preserved as internal moulds.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP wil

Fig. 63. Metacryphaeus caffer (Salter). An internal mould

in the collection of R. Dick, Cape Town. x 1.

Metacryphaeus convexus (Ulrich) (1893: 16, pl. 1 (figs 9-11)) was based

upon two isolated cephala and a pygidium drawn with an entire margin. As

figured by Groth (1912, pl. 18 (fig. 4), pl. 19 (fig. 1)) and Wolfart (1968: 94, pl.

12 (fig. 1)), however, this species differs from M. caffer in having the sagittal

area of the glabella, between the adaxial terminations of the glabellar furrows,

strongly inflated and raised, with a tendency for the 2p furrows to be deepest

abaxially and distinctly connected with the axial furrows.

Metacryphaeus dereimsi (Groth) (1912: 606, pl. 18 (figs 1-3)) was based

upon isolated pygidia association with M. convexus. The post-axial field seems

rather more triangular than is typical for M. caffer and thus this species closely

approaches M. venustus. However, since most Metacryphaeus species have

closely comparable pygidia, this name is probably best regarded as a nomen

dubium.

Metacryphaeus praecursor Wolfart (1968: 82, pl. 8 (fig. 7)) was based upon

an isolated cephalon which differs from M. caffer in having the 2p and 3p

92 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 64. Metacryphaeus caffer (Salter). A. SAM-—PDB4335. B. SAM-PDB4352.

C. SAM-PDB4340. D. SAM-PDB4075. E. SAM-PDB4363. F. SAM-PDB4354,

in lateral view. G. SAM—PDB4329. H. SU-C2, the holotype of Dalmanites (Probo-

loides) ensifer Reed in lateral view. All preserved as internal moulds and all x 1,3.

93

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

‘spynowr [euroqur se paarosord [PV “O°T x “(OL SY) 6 ‘Id “YSZHT S.P2e¥ JO [BUISIIO OY) ‘OGLL-NVWS “A ‘FI X “LEOPAdd-WVS ‘O

‘(1oyes) 4affv2 snapyddsovjay “G-D “61 X “aANyNS [RIOR] oy} JO snes JOLID]UR dy} WoIy payesedas [Jam st ey} 9qo] [RIVOLI a1R[NDIAqN}

IY) AION “(p9o2y) Ming vjyjauing jo sadAyuds pansy ((¢ “3y) 6 ‘Id ‘vSZI) S,peeY JO 9UO ‘O8//-WYS ‘(ZIeMYOS) sasad sidsp1ysmojz0y

‘

‘pod “TX “winasnyy uKoY YINog ay} ur ‘((¢ “B3Yy) pZ “Id ‘pO6L) BAeT JO [euIsiIO oY], “(preMpooM) YjV8vISIUD DYaUuIDg “YW ‘Sg “314

94

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 66. A. Metacryphaeus caffer (Salter). AM-—69, plaster cast of an external mould in

nodule preservation. Note the weak ocular ridge. B. Bainella africana (Salter). Latex

cast of the holotype of Phacops acacia Schwarz, AM-—2124, preserved as an external

mould, and figured by Schwarz (1906, pl. 10 (fig. 4)) and Rennie (1930, pl. 10 (fig. 5)).

Note how both these workers misinterpreted the nature of the genal spines, which are

situated inside (adaxial) of the genal angles and were almost certainly recurved distally.

Both X 1,7.

95

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

‘ST X ‘Spfnoul jeusojut

SP paalosaid (7 BY) 6 ‘Id ‘yCZH] sty Jo speuIsIUO ay) pu ‘(podxyz) luipq vyjauwg jo satias adAjudAs datsuajxo s.paay jo yaed BurmM0j

“Sp[NOwW [BUIIIUL se poatosoid ‘vyeydao yo dnois ve ‘QOZL-WVS ‘(491[eS) UDO “Jo pyauwg °{ “ST x ‘layes ipuvjjuad “yo (snavyd&up)

sajuvuyog se ((OT “3y) [1 ‘Id ‘ysz6t) peoy Aq painsy pyjnow jeusa}xo 241 “€9P7-NVS ‘(4aIeS) daffpa snanyddisvjaw “vy °L9 “314

96

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 68. A. Bainella africana (Salter). RO-708, showing the visual surface

of the eye. Much enlarged. B. Metacryphaeus caffer (Salter). SAM-—

PDB4341. X 1,8. Both preserved as internal moulds.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP ay

Fig. 70. Aff. Metacryphaeus caffer (Salter). SMC-A3063, the ros-

tral fragment figured by Reed (1925a, pl. 8 (fig. 2)) as D. (Cry-

phaeus) cf. rostratus Kozlowski, associated with a cephalon of

Bainella ‘baini’ (Reed). Both preserved as internal moulds. x 2.

98 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 71. Metacryphaeus giganteus (Ulrich).

A reconstruction based upon the figured material of Wolfart (1968).

x 1,8.

glabellar lobes rather inflated, with the L1 lobes narrow and reduced. M.

curvioculatus (Wolfart) (1968: 76, pl. 6 (fig. 2)) is very close to M. venustus and

differs from M. caffer in much the same respects as the latter species.

Metacryphaeus giganteus (Ulrich) (1892: 14, pl. 1 (figs 6-8)) (Fig. 71

herein) is very close to M. caffer, at least some of the differences relating to the

nodule preservation of the Bolivian material. However, it may be distinguished

from the South African species by its more rounded frontal lobe and in the

development of seemingly true genal spines. Its occipital furrow also appears to

be relatively broader (sag.).

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 99

Fig. 72. Punillaspis argentina (Baldis).

A reconstruction based upon the figured material.

x 2.

Metacryphaeus tuberculatus (Kozlowski) (1923: 43, pl. 3 (figs 20-21)) was

originally described as a variety of M. australis (Clarke) but elevated to specific

status by Wolfart (1968). As figured by Kozlowski (1923), the cephalon is

indistinguishable from M. caffer, while the pygidium merely differs in its

slightly more triangular outline (an artefact of nodule preservation?). The

cephala figured by Wolfart (1968: 102, pl. 17 (fig. 7), pl. 18 (fig. 1)) cannot

satisfactorily be separated from M. caffer and should probably be regarded as

conspecific. However, since N. Eldredge of the American Museum of Natural

History is currently revising the Bolivian calmoniids, the taxonomic position of

this species should await his conclusions.

Metacryphaeus argentina Baldis (1967: 792, pl. 1 (figs 7-11), pl. 2 (figs

1-6)) (Fig. 72 herein) is a curious species whose very reduced, minute eyes

readily distinguish it from M. caffer and, indeed, all other species of Metacry-

100 ANNALS OF THE SOUTH AFRICAN MUSEUM

phaeus. It was recently (Baldis & Longobucco 1977a) made the type of the new

genus Punillaspis.

Occurrence

Metacryphaeus caffer (Salter) is abundant in the Voorstehoek Formation of

the Bokkeveld Group, and the probably conspecific M. tuberculatus (Kozlow-

ski) ranges from the upper part of the Belen Formation into the Sicasica

Formation of Eifelian age in Bolivia. There is definitely a Metacryphaeus

species present in the Gydo Formation but none of the material available to the

writer has been sufficient to identify M. caffer positively; it could be M. gigan-

teus (Ulrich) to judge by the stratigraphic relationships of the various species of

Metacryphaeus in Bolivia.

Metacryphaeus (Metacryphaeus) venustus Wolfart, 1968

Figs 73-75, 76A, C-D, 77C-D, F, 78B-—C

Cryphaeus australis Clarke, Kozlowski, 1923: 41, pl. 3 (figs 3-6, 8, 14-17). Reed, 1925a: 139

(pars). Fricke et al., 1964: 15-16.

Metacryphaeus australis (Clarke) Branisa, 1960: 68, 74.

Metacryphaeus caffer (Reed) Braniga, 1960: 66, 71; 1965: 106, pl. 21 (figs 10-15). Fricke et al.,

1964: 16.

Metacryphaeus venustus Wolfart, 1968: 99, pl. 15 (figs 2-4), pl. 16, pl. 17 (figs 1-6). Eldredge &

Ormiston, 1979: 160.

Material

Fourteen specimens, PRV-—716, 718-719, 721, 724, 729, 731-734, 777, 780,

791, and 796, all preserved as internal moulds, and all from the Waboomberg

Formation at Klein Tafelberg.

Description

Cephalon. The cephalon is semicircular, much broader (trans.) than long

(sag.), with the cephalon diverging strongly to the anterior. The frontal lobe is

subrhomboidal, with a prominent posterior median impression and no distinct

auxiliary impression system. The 3p furrows are deep, directed postero-

medially, and distinctly connected to the well-developed axial furrows. The 2p

furrows are deep, transverse, and connected to the axial furrows, while the 1p

furrows are very deep, anteriorly concave, and also distinctly connected to the

axial furrows. The occipital furrow is arched forward sagittally and with deep

apodemal pits distally. The L1 lobes are very narrow (exsag.), anteriorly

concave, and in some individuals give the impression of being weakly con-

nected across the glabella (Fig. 76A, C). The L2 lobes are more or less of

constant width, and the L3 lobes broaden (exsag.) distally. The median

glabellar region, between the adaxial terminations of the L2 and L3 lobes,

seems to be slightly raised in some individuals (Fig. 77C). The occipital furrow

is arched forward sagittally, and with deep apodemal pits distally. The occipital

ring is of constant width (exsag.) and lacks tuberculation. There is a narrow

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 101

Fig. 73. Metacryphaeus venustus Wolfart.

A reconstruction based upon the material from

the Waboomberg Formation. x 2.

anterior border that, in some of the better preserved cephala (Fig. 76A), shows

the hint of a very short, median rostrum.

The cheeks are subtrigonal and curved strongly downward distally. The

posterior border furrows are deep, transverse, whereas the lateral border

furrows are shallow and indistinct. The posterior border broadens (exsag.)

rather markedly towards the genal angles. In PRV-796 (Fig. 75), the genal

angles are produced posteriorly, with a rather distinct spinule. The eyes are

large, about 40 per cent of the exsagittal cephalic length, and comprise

subvertical rows of ocelli, with 6-7 lenses in the middle row. In PVR-796 only

about 18 rows of ocelli could be counted. The anterior branch of the facial

suture is not clearly visible in any of the available material; presumably it was

in close juxtaposition with the glabellar frontal lobe. The posterior suture

curves strongly forward after leaving the eye, and then recurves to meet the

lateral border approximately opposite the posterior margin of the eye.

102 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 74. Metacryphaeus venustus Wolfart. PRV-791, preserved as an

internal mould. x 2.

Thorax. There is little to separate the thorax of Metacryphaeus venustus

from that of M. caffer, and hence it does not merit redescription.

Pygidium. The pygidium is wider (trans.) than long (sag.), with a convex

axis that tapers strongly to the posterior for the first 5 rings, whereafter the

distinct axial furrows become subparallel. After the eighth axial ring the

segmentation becomes indistinct but there may have been as many as 11 rings;

certainly in some individuals 10 can be counted. The anterior 4 ring furrows

have apodemal pits distally and the axis is bluntly terminated to the posterior,

leaving a very pronounced post-axial field. The pleural fields are subtrigonal

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 103

Fig. 75. Metacryphaeus venustus Wolfart. PRV-796, preserved as an internal mould. Note the

very reduced L1 lobes, large eyes, and distinct spines to the genal angles. x 3.

104 ANNALS OF THE SOUTH AFRICAN MUSEUM

and rather strongly convex. There are 6 distinct pleurae, each with a pro-

nounced pleural groove and faint interpleural furrows, with a very reduced

seventh to the posterior. The anterior 5 pairs of pleurae terminate in prominent

lappets distally. In PRV—724 there are weak, oblique tubercles, on the anterior

moiety of each pleura (Fig. 78B), marking the fulcrum. This feature is not,

however, persistent and its taxonomic significance is uncertain. The post-axial

field is relatively rather broad, about 22 per cent of the sagittal length of the

pygidium, and appears to be abruptly truncate to the posterior (Fig. 78C).

Discussion

The Bokkeveld material shows a few minor points of differences when

compared with the Bolivian material. These include apparently fewer lenses to

the eyes and the presence in at least one individual of weak tubercles marking

the fulcral axis of the pygidium. In view of the remaining marked similarities

between the two forms, however, the differences are not at present considered

of taxonomic importance. Differences from the other species of Metacryphaeus

are discussed under M. caffer.

Occurrence

Metacryphaeus venustus Wolfart is currently known only from the upper

part of the Belen Formation and the Sicasica Formation of Bolivia, and the

Waboomberg Formation of South Africa.

Metacryphaeus (Metacryphaeus ?) cf. koukharskii (Baldis & Longobucco, 1977)

Figs 76B, 77A-B, 79

Compare

Acastoides koukharskii Baldis & Longobucco, 1977b: 171, figs 1-3.

Material

Two specimens PRV-175 and 428, both preserved as internal moulds, the

latter from the farm Bon Chretien, 15 km due east of Ceres, south-western

Cape.

Description

Cephalon. The cephalon is subtrigonal in outline and rather convex, with

strongly downturned cheeks. The axial furrows are pronounced and diverge

anteriorly. The glabella is convex, with a somewhat inflated frontal lobe that is

oval in shape and without a distinct auxiliary impression system. The 3p

furrows are weakly impressed, straight, and directed anterolaterally to connect

with the axial furrows. The 2p furrows are moderately impressed, transverse,

anteriorly convex, and distally connected with the axial furrows. The 1p

furrows are very deep, transverse, and strongly connected to the axial furrows.

105

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

“sp[now [eusd}UT se

paarasaid [py °Z x “wmuprsdd peordAy & *76—-A Ud ‘(491[eG) PUotfo vYJaUIDY “| “ZX “SLI-AUd ‘(OsonqosuoT 7 sipjeg)

IL{SADYYNOY “JO snavyddsovjaw “| *7X “LLL

“Aud “7X ‘TeL-AUd ‘DO 'S‘€ X “MOLI IE[Poqe|sueN jounsIp ev Aq

paysouuos Ayjeurxoid ose smosiny dy oy) MOY 210N “O8/-AUd “W “MWeOA snisnuaa snavyddiovjaew ‘G-D ‘V '9L ‘314

106 ANNALS OF THE SOUTH AFRICAN MUSEUM

5, oe

Fig. 77. A-B. Metacryphaeus cf. koukharskii (Baldis & Longobucco). PRV-—428. Note the

abaxial taper of the L2 lobes and the connection of the 2p furrows with the axial furrows. C-D,

F. Metacryphaeus venustus Wolfart. C. PRV-796. Note the very reduced L1 lobes.

D. PRV-729. F. PRV-733. E. Bainella africana (Salter). PRV-—57. All preserved as internal

moulds and all x 2.

107

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

‘parejs dSIMIOYIO ssoyuN Z x [[B pue Sp_NOU [eUIa}UI se paArosoid

ITV ‘wojsds uolssoidun Areyixne podojaasp-[[am eB SUIMOYS ‘7Z76-AUd ‘(4aIeS) /affva snavydduonjaw “q “¢ x ‘sapreqny

[eropny Suryory sjduexs uy “gT/-AUd ‘DO ‘SEXe [esO[NJ ay) 3 saposoqmy anbiygo ‘a eBuoja oy) SION ‘pZL-AUd ‘GF “URIOAA

—AUd ‘(191[8S) vuvoufo vyjauig “VW SL ‘S14

snisnuaa snavyddsovjay ‘Q-q ‘(peey) jung, ‘g Jo sadAquds ayl Jo auo ‘/6T¢

108 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 79. Metacryphaeus cf. koukharskii (Baldis & Longobucco).

A reconstruction based upon PRV—428.

<r

The L1 lobes are moderately broad (exsag.) and of more or less constant width,

and the L2 lobes characteristically narrow abaxially. There is no posterior

median depression to the frontal lobe. The occipital furrow is deep, anteriorly

convex, of constant width, and with deep apodemal pits distally. The occipital

ring is smooth and of approximately constant width (exsag.). The cheeks are

subtrigonal in outline, strongly downturned, and with deep, transverse poster-

ior border furrows. The lateral border furrows are poorly developed and,

although not preserved, the genal angles give the impression of having been

subrounded. The eyes are moderately large, about 50 per cent of the exsagittal

length of the cephalon, and situated opposite the L2 and L3 lobes. The anterior

ramus of the facial suture could not be discerned, but the posterior branch

meets the lateral border opposite the posterior margin of the eye.

Discussion

The Bokkeveld example closely resembles the holotype of Baldis &

Longobucco (1977b), from which it seemingly differs only in being more

strongly convex and with more sharply down-turned cheeks. These features

may, however, be artefacts of preservation and, allowing for a moderate range

of intraspecific variation, the Bokkeveld example may reasonably be compared

with the Argentine species.

The generic assignment of ‘Acastoides’ koukharskii is difficult; it does not

belong to the Boreal Acastoides, which differs in having weakly impressed 2p

furrows that do not connect with the axial furrows, and with very reduced L1

lobes. In both Pennaia and Phacopina the 2p furrows typically become obsolete

distally, with the fusion of the L2 and L3 lobes. It thus finds its closest ally in

Metacryphaeus venustus Wolfart, a somewhat atypical Metacryphaeus in the

strongly reduced nature of its L1 lobes and the distinct connection of the 2p

furrows with the axial furrows. None the less, assignment of ‘A’. koukharskii to

the genus Metacryphaeus seems reasonable.

Occurrence

Metacryphaeus koukharskii (Baldis & Longobucco) is currently recorded

from an uncertain level in Argentina, but may also be present in the Bokkeveld

sequence of South Africa.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 109

Genus Typhloniscus Salter, 1856

Type species Typhloniscus baini Salter, 1856; by monotypy

Typhloniscus baini Salter, 1856

Figs 7B, 33E-F, 39C, 41B-C, 50E, 80-82

Typhloniscus baini Salter, 1856: 221, pl. 25 (fig. 14). Lake, 1904: 213, pl. 25 (figs 8-9). Clarke,

1913: 158. Reed, 1925a: 162; 1927: 347. Rennie, 1930: 355, pl. 10 (figs 6-12). Struve (in

Harrington ef al.), 1959: 0487, fig. 385,1.

Acaste (Typhloniscus) baini (Salter) Kozlowski, 1923: 31.

Acidaspis atherstonei Reed, 1925a: 188, pl. 7 (fig. 7).

Acidaspis capensis Reed, 1925a: 189, pl. 11 (figs 6-7).

Material

The holotype, by monotypy, BM-—28635, together with BM-—In24103-—4,

SU-K463, SAM-7186, 7799, 8978, 8982-8983, PRV-624-625, AM-2561, and

RO-3, 702, 753-754, 757, 782, 793-794, 796, and P3.

Description

Cephalon. The cephalon is subpentagonal in outline and more than twice as

wide as the sagittal length. The glabella is pentagonal in outline, weakly convex,

and with straight axial furrows that diverge slightly to the anterior. On internal

moulds the axial furrows are very deep (Fig. 81), whereas where the cuticle is

preserved (Fig. 33F) they are broad and shallow. The 3p glabellar furrows are

moderately deep, directed posteromedially at about 45° to the axial furrows and

weakly connect to the axial furrows. On internal moulds the 2p furrows are

straight, directed posteromedially at about 60° to the axial furrows, weakly

connected to the axial furrows, and with very deep adaxial apodemal pits. The 1p

furrows are parallel to and similar in all respect to the 2p furrows. On internal

moulds the occipital furrow is broadest sagittally, but where the cuticle is

preserved it is of uniform width and with distal apodemal pits. The occipital ring

is of uniform width on internal moulds, but where the cuticle is preserved is

biconvex and several times broader than the occipital furrow sagittally.

Curiously, the deep posterior border furrows of the cheeks do not connect with

the occipital furrow due to narrow branches of the occipital ring that connect in

this position. The posterior border furrows are well developed and deep, but the

lateral border furrows are broad, shallow and indistinct. The posterior borders

broaden rapidly towards the genal angles that are produced backward and

sharply rounded. The genae, which are entirely on the fixigenae, are raised and

strongly convex, with scattered pits on the internal mould but a coarsely

granulose cuticle. Eyes are apparently lacking but there are small ridges at the

extreme anterior of the cheeks, opposite the distal terminations of the 3p furrows,

which are separated from the cheek area by shallow grooves. They may represent

relict ocular ridges. There is a very narrow anterior border with the vaguest hint of

a median frontal process. The facial suture runs along the dorsal surface of the

anterior border and becomes inframarginal opposite the ‘eye ridges’.

110 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 80. Typhloniscus baini Salter.

A reconstruction based upon the available material.

ae

Thorax. The thorax tapers rather rapidly to the posterior, as does the axis

which is about one-third the thoracic width. The axial rings are thickest along

their posterior borders and separated by much wider ring furrows, with deep

apodemal pits distally. The pleurae have moderately well-developed pleural

grooves and distinct interpleural furrows. The posterior moiety of each pleura

broadens (exsag.) and thickens distally and, after the fulcrum, bears 1-3 tiny

tubercles, well shown by PRV-624. The pleurae have pointed distal termina-

tions and, where the cuticle is preserved, are coarsely granulose.

Pygidium. The pygidium is small, micropygous, with an almost semicircu-

lar outline. It is somewhat wider than the sagittal length and with an entire

margin. The axis is very prominent, cylindrical, and tapers only very slightly to

the posterior. It comprises 4 prominent rings, slightly wider than the ring

furrows, the anterior three of which preserve apodemal pits. A variably

developed fifth ring is pronounced on some individuals but very reduced and

insignificant in others. The axis increases in height posteriorly and has a bluntly

rounded terminal end which tends to overhang the pygidial margin. The pleural

fields comprise 3 pairs of very prominent, raised ribs that increase in height

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP att

Fig. 81. Typhloniscus baini Salter. The holotype and original

of Salter (1856, pl. 25 (fig. 14)), preserved as an internal

mould; housed in the British Museum (Natural History). x 2.

distally and are separated by slightly narrower, deep interpleural grooves. The

pleural furrows seem to be obsolete. A fourth very reduced pair of pleural ribs

is generally present.

Discussion

The writer has had the opportunity of studying the holotypes of both

Acidaspis atherstonei Reed, BM-In24103, and A. capensis, SAM-7799, and it is

clear that both species are based upon isolated thoraxes of Typhloniscus baini.

Except for some species of the homoeomorphic Ordovician genus Placoparia

and ‘Typhloniscus’ princeps Reed (1908: 433, pl. 14 (figs 1-3)), (a Cheirurus ?),

there are no species with which the present form warrants comparison.

Occurrence

Typhloniscus baini Salter is currently known only from the Gydo Forma-

tion of the Bokkeveld sequence.

ANNALS OF THE SOUTH AFRICAN MUSEUM

2

‘97 X ‘avInayd

M9B1OYI IY} JO SoNIOW JoLI}sod ayy 0} saposaqni JOUNSIP oy} puK ,sadpll a49, dy} 210N “PZ9O-AUd “IayeS ling snosiuojydd] *7g “B14

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP MIB)

Genus Phacopina Clarke, 1913

Type species Phacops braziliensis Clarke, 1890;

by original designation

Discussion

The writer is, at present, unhappy with the treatment of this genus by

Eldredge & Branisa (1980). These authors would regard Jujuyops, type species

J. nonoctubrensis Baldis, Benedetto, Blasco & Martel (1976, pl. 5 (figs 1-4)), as

a junior subjective synonym of Phacopina, noting that their Phacopina convexa

may be conspecific with J. nonoctubrensis. However, P. convexa Eldredge &

Branisa differs markedly from P. braziliensis in having much smaller eyes

(27-34 % of the exsaggital cephalic length as against almost 50%, to judge from

Eldredge & Brani§a’s illustrations) that are situated far forward (39% of the

exsagittal cephalic length from the posterior margin of the cephalon to the

posterior limit of the eye, whereas the eyes of P. braziliensis almost touch the

posterior border furrows). Moreover, the glabellar segmentation of Jujuyops is

more pronounced with transversely longer lp furrows, its axial furrows are

subparallel and do not diverge strongly towards the anterior as in P. brazilien-

sis, and its Ll lobes are much broader exsagittally (14% of the sagittal length of

the glabella as against only 8,3% in P. braziliensis). To judge from other

calmoniid trilobites, these differences warrant, in the writer’s opinion, generic

separation. Since N. Eldredge is currently revising Clarke’s Brazilian material,

further comment must await the appearance of his work and the South African

material is referred to the oldest available name, Phacopina.

Phacopina hexensis (Reed, 1925)

Fig. 83

Proetus hexensis Reed, 1925a: 121, pl. 7 (fig. 8).

Material

Reed’s two syntype pygidia, SU-H176 and SAM-3889, of which the

former is herein selected as lectotype.

Description

This species is based upon pygidia and the characters of the cephalon and

thorax are currently unknown. The lectotype is moderately convex, semicircu-

lar in outline, and with an entire margin. The axis is broad anteriorly but tapers

rapidly to the posterior to terminate in a bluntly rounded tip short of the

posterior margin so as to leave a distinct post-axial field. On the lectotype, only

the first two axial rings, separated by narrow ring furrows, are reasonably

distinct, as well as the first two pairs of pleural grooves. The remaining

segmentation is very indistinct to obsolete. The pleural grooves do not reach

the pygidial margins, so that there is a smooth border strip. The surface of the

pygidium is very finely granulose, the lectotype retaining much of the cuticle.

114 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 83. Phacopina hexensis (Reed). SU-H176, the lectotype and orig-

inal of Reed’s 1925a, pl. 7 (fig. 8) which retains much of the cuticle.

x 2,5

Discussion

The lectotype pygidium of Phacopina hexensis is virtually identical to that

of P. convexa Eldredge & BraniSa (1980, fig. 22K) (Fig. 84 herein) and also to

that of Andinacaste chojnacotensis (Swartz) (1925: 50, pl. 1 (figs 8-10); Wolfart

1968: 122, pl. 23 (figs 4-6), pl. 24 (figs 1-4)). Complete examples of the South

African species are required, however, before it can be usefully compared with

the South American material.

Occurrence

Phacopina hexensis (Reed) is currently a South African endemic from an

uncertain level in the Bokkeveld sequence.

Phacopina lakei (Reed, 1925)

Figs 59A, 85A-B, D, 86-87A, C-D, 88

Phacops (Calmonia) lakei Reed, 1925a: 154, pl. 9 (figs 4-5).

Material

The holotype, SAM-7791 (Fig. 85A), by lectotype designation herein,

together with SAM-—PDB570, 4305a, b and PRV-21, all preserved as internal

moulds.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 115

Fig. 84. Phacopina convexa Eldredge & Branisa.

A reconstruction based upon the figured material.

x3.

Description

Cephalon. The cephalon is semi-elliptical in outline, weakly convex, and

with a length/width ratio of about 0,50. The axial furrows are moderately

impressed, straight, and diverge slightly to the anterior. The frontal lobe is

elliptical to subrhomboidal, with no discernible auxiliary impression system.

The glabella is distinctly wider (trans.) than long (sag.), with a length/width

ratio of 0,84. One of the most distinctive features of this species are the 3p

furrows which are distally strongly impressed and connected to the axial

furrows. Adaxially, however, they are very fine and weakly impressed, and

barely discernible. This gives the impression of very short 3p furrows. The 2p

furrows are lightly impressed, anteriorly convex to almost straight, and do not

connect with the axial furrows, with the result that L2 and L3 coalesce distally.

The Ip furrows are very deep, anteriorly concave, and strongly connected to

the axial furrows. The L1 lobes are rather narrow (exsag.), broadening slightly

116 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 85. A-B, D. Phacopina lakei (Reed). A. SAM-7791, the lectotype and original of Reed

(1925a, pl. 9 (fig. 4)). x 2,3. B, D. PRV-21. Note the short 3p furrows, distinct anterior

border, large eyes, convex anteriorly 2p furrows and long (trans.), narrow L1 lobes. X 2,6.

C. Oosthuizenella ocellus (Lake). PRV-37. X 2,6. E-F. Phacopina? sp. nov? PRV-119. Note

the deeply impressed 2p furrows, sagittal ridge to the median area and truncate frontal lobe.

x 2,6. All preserved as internal moulds.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP MAY

Fig. 86. Phacopina lakei (Reed). A. SAM-PDB4305a. B-C. SAM-

PDB4305b. Both preserved as internal moulds and both x 2,6.

ANNALS OF THE SOUTH AFRICAN MUSEUM

118

“spynoul

jeusiajur se poasosaid susuoeds Ty ‘st x “((9 SY) 6 ‘1d ‘vgZ6I) parry tadupys (Zpiajnog) sdoovyg Jo adAjo,d9] IY)

‘P6LL-NVS ‘atuuoy sisuapyuns vyjauing “JO “ZX ‘RIEqe|s ay) JO yIpeoig pur ‘sMorny dz xaauod ApJOLajue ‘possosdut

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 119

Fig. 88. Phacopina lakei (Reed). SAM-PDBS570, a crushed example with a

mineralized cuticle. The associated pygidium is too poorly preserved for

satisfactory identification but may belong here. x 2,5.

abaxially. The occipital furrow is moderately deep, arched forward sagittally,

and with deep apodemal pits distally. The occipital ring is smooth and broadest

sagittally. The cheeks are moderately convex, weakly down-turned, with deeply

impressed posterior border furrows that curve forward distally. The lateral

border furrows are shallow and ill-defined. The posterior border is prominent,

broadening (exsag.) abaxially, as are the lateral borders. There is a distinct,

narrow, anterior border that is visible in dorsal view. The eyes are relatively

large, about 40 per cent of the exsagittal length of the cephalon. The writer was

unable to discern the small profixigenal spines which were alleged to occur

(Reed 1925a: 155) just posterior to the intersection of the facial suture with the

lateral border. There is no evidence for the anterior branches of the facial

sutures cutting the lateral extremities of the frontal lobe, and the posterior

branches meet the lateral borders slightly in front of the posterior margins of

the eyes.

Discussion

This species is currently known only from cephala and hence may be based

upon a different part of the same animal as Phacopina hexensis (Reed). Until

more material is available, however, it is retained as distinct.

ANNALS OF THE SOUTH AFRICAN MUSEUM

120

“Sp xX ‘(paey) 1ayn] vuidoopyg Jo adAyuAs painsy ((¢ “3Y) 6 “[d ‘vSZST) s.paay ‘Jepur ‘antl -ds yvwuuag ‘g

‘(QyVq) snainquy vyJauIwg “Y ‘68 “sly

TX ‘pynow jeusajur ue se paasasoid “((p By) pz Id “pO6T) PVT JO [eUIsIO oy) *g/1L-NVS

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 121

Phacopina is closely related to Pennaia and they seem to be sister taxa,

perhaps both derived from the Silurian Andinacaste. As such they share many

features in common and, in the absence of complete specimens, discrimination

is not always easy. The present species is assigned to Phacopina because of its

very broad (trans.) cephalon and glabella, the latter bluntly rounded anteriorly

and with a distinct anterior border. The L1 lobes are narrower (exsag.) and

longer (trans.) than is typical of Pennaia, and the 2p furrows are much more

weakly impressed.

Reed’s (1925a) small, figured syntype (Fig. 89B) of Phacopina lakei

emphasizes this problem. Reed considered this example to have an entire

pygidium but, as can be seen from Figure 89B, the margins are obscured by

matrix. As such it is uncertain whether the border was entire, as in Phacopina,

or with minute spinules, as in Pennaia. The presence of at least 6 axial rings

and 5 distinct pairs of pleural ribs to the pygidium tends to suggest that this

specimen is a juvenile Pennaia. This is supported by the straight 2p furrows and

posterior border furrows to the cephalon. As such the writer is inclined to

identify this specimen as Pennaia? sp. juv. indet.

Occurrence

Phacopina lakei (Reed) is currently known with certainty only from the

Voorstehoek Formation of the Bokkeveld sequence.

Phacopina? sp. nov?

Figs 85E-F, 90

Material

A single cephalon, PRV-—129, preserved as an internal mould, from the

Hottentotskloof, 30 km north-east of Ceres.

Description

Cephalon. The cephalon has been slightly crushed, but was clearly much

wider (trans.) than the sagittal length, and moderately convex. The glabella is

subtrapezoidal in outline, with straight, rather deep axial furrows diverging

Fig. 90. Phacopina? sp. nov?

A reconstruction of the cephalon based upon PRV-119.

xe:

122 ANNALS OF THE SOUTH AFRICAN MUSEUM

anteriorly and an abruptly truncate, weakly convex anterior margin. It is

longer than wide, with a length/width ratio of 1,05, and a distinct sagittal

ridge to the median glabellar area. The 3p furrows are very poorly deve-

loped, almost obsolete; they are sinuous and directed strongly postero-

medially, and weakly connected to the axial furrows. The 2p furrows are

moderately impressed, anteriorly convex, and weakly connected to the axial

furrows. The lp furrows are very deep and directed strongly posterome-

dially, so that the L1 lobes broaden (exsag.) considerably abaxially, and are

distinctly connected to the axial furrows. The occipital furrow is broad,

anteriorly convex, and with deep apodemal pits distally. The occipital ring is

poorly preserved, but seems to have been smooth and of more or less

constant width. The cheeks are subtrigonal, weakly convex, and with deep,

straight posterior border furrows and subrounded genal angles. The eyes are

poorly preserved, but seem to have been about one-third of the exsagittal

length, while the facial sutures could not be discerned. The surface of the

cephalon is finely granulose.

Discussion

The present example differs from Phacopina lakei (Reed) in having a

glabella that is longer than wide (trans.), with almost obsolete 3p furrows and

moderately impressed 2p furrows that weakly connect with the axial furrows, a

sagittal ridge to the median glabellar region, L1 lobes that broaden (exsag.)

markedly distally, and straight posterior border furrows to the cheeks.

‘Acastoides’ koukharskii Baldis & Longobucco (1977b: 171, figs 1-3) bears

a superficial resemblance to the above example, but has deeply impressed 3p

furrows, and an ellipsoidal to rhomboidal frontal lobe, while lacking a sagittal

ridge to the median area.

Phacopina padilla Eldredge & BranisSa (1980: 251, fig. 24A—-F) has a more

rounded cephalon, larger eyes, narrower (exsag.) L1 lobes, weaker 2p furrows

that become obsolete distally, and genal spines. Phacopina convexa Eldredge &

Branisa (1980: 248, figs 2B, 22-23A) also has a more rounded cephalon and

weaker 2p furrows that become obsolete distally, with the fusion of the L2 and

L3 lobes.

Phacopina braziliensis (Clarke) (Eldredge & Branisa 1980: 240, figs

20A-C) has much larger eyes placed further backward, obsolete 2p and 3p

furrows, transverse 1p furrows and narrow (exsag.) L1 lobes, and a more

rounded cephalon than the present material.

Phacopina cf. padilla Eldredge & Branisa, 1980

Figs 91-92

Compare

Phacopina padilla Eldredge & Branisa, 1980: 251, fig. 24A-F.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 123

Material

A single internal mould, SAM-—8965, in black carbonaceous shale and thus

from the Gydo Formation.

Description

Only the cephalon is known from South African material. It is semicircular

in outline, weakly convex, and with a glabella that expands slightly to the

anterior. The axial furrows are fairly deeply impressed, except between the

eyes and L3 lobes where they become almost obsolete. There are distinct axial

furrow pits. The 3p furrows are rather weakly impressed, almost straight, and

directed strongly posteromedially; they appear to connect weakly with the axial

furrow pits. The 2p furrows are straight, transverse, and distally obsolete, with

Fig. 91. Phacopina cf. padilla Eldredge & Branisa.

A reconstruction of the cephalon based upon SAM-8965.

xe

Fig. 92. Phacopina cf. padilla Eldredge & Braniga. SAM-—8965, preserved as

an internal mould. Note the spiniform processes to the genal angles, the large

eyes, moderately impressed 3p furrows, and the weakening of the axial

furrows opposite the L3 lobes. Dorsal views x 5, lateral view of visual surface

of eye approx. x 8.

124 ANNALS OF THE SOUTH AFRICAN MUSEUM

the abaxial fusion of the L2 and L3 lobes. The 1p furrows are very deep,

transverse, slightly concave to the anterior, and strongly connected to the axial

furrows. The occipital furrow is deep, broadest sagittally, and with apodemal

pits distally. The smooth occipital ring is somewhat inflated, and broadest

sagittally. The cheeks are rather convex, with deep posterior furrows that are

slightly concave to the anterior, and broad, shallow, indistinct lateral furrows.

The posterior borders broaden (exsag.) slightly abaxially, and the well-rounded

genal angles bear minute spines. The eyes, situated between the lp and 3p

furrows are large, about 50 per cent of the exsagittal length of the cephalon,

and strongly arcuate. The palpebral lobes lie in the same horizontal plane as

the median area of the glabella. The visual surface of the eye comprises about

25 vertical files, with 6 ocelli in the central file. The anterior ramus of the facial

suture may, just, transect the lateral edge of the frontal lobe, while the

posterior branch is initially directed anterolaterally, before recurving strongly

to meet the lateral margin just in front of the genal spinules.

Discussion

The very small size, large eyes, and minute genal spines suggest compari-

son of the Bokkeveld example with Phacopina padilla Eldredge & Brani§a. It

differs from the Bolivian material mainly in having more deeply impressed 2p

and 3p furrows, and distinct axial pits opposite the distal terminations of the 3p

furrows. The differences are slight and probably due to intraspecific variation

and differences in preservation.

Phacopina correlator (Clarke) (Eldredge & BraniSa 1980, fig. 20F—-G) from

the Oriskany of Becraft Mountain is also very close to the present species. It

seems to differ mainly in the greater expansion of its frontal lobe, with slightly

smaller eyes, and subacuminate genal angles that apparently lack spinules.

Occurrence

Phacopina padilla Eldredge & Brani§a is currently known from the lower

part of the Icla Formation at Padilla, Bolivia, and perhaps from the Gydo

Formation of the Bokkeveld sequence.

Genus Renniella gen. nov.

Type species Renniella rossouwi gen. et sp. nov.

by original designation herein

Diagnosis

A calmoniid with a strongly inflated, protuberant, frontal lobe showing a

typical calmoniid auxiliary impression system. There is a pronounced posterior

median impression that is connected to the proximal ends of the 3p glabellar

furrows and serves to isolate the frontal lobe. The glabellar axial furrows are

moderately deep, diverging strongly to the anterior, and with deep axial furrow

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 125

pits at the distal terminations of the 3p furrows. The latter are strongly

impressed, but weaken distally and connect only very faintly with the axial

furrows. The 2p furrows are transverse, deepest medially and becoming effaced

distally. The lp furrows are deep, short, parallel to the 2p furrows, and

distinctly connected to the axial furrows. Proximally, the 1p furrows show a

weak bifurcation. There is a small but distinct tubercle (spine base?) between

the medial bifurcations of the Ip furrows. The L3 lobes broaden (exsag.)

distally where they coalesce with the L2 lobes which are of constant width. The

L1 lobes are relatively broad (exsag.) and also of constant width. The occipital

furrow is transverse with deep apodemal pits distally. The eyes seem to have

been raised on palpebral prominences and appear to be small, only about

one-quarter of the exsagittal length of the cephalon. The characters of the

genae and facial sutures are unknown. Certainly, the anterior branch of the

facial suture does not transect the lateral corners of the frontal lobe. The

anterior border is very narrow and overhung by the frontal lobe.

Etymology

The generic name Renniella is for Professor J. V. L. Rennie, vice-

chancellor of Rhodes University, Grahamstown, who contributed greatly to an

understanding of the Bokkeveld trilobites. The specific name is for Mr P. J.

Rossouw of the Geological Survey, Pretoria, who has added much to our

knowledge of the Bokkeveld succession.

Discussion

Renniella is very close to Tarijactinoides, as redescribed and rediagnosed

by Eldredge & Branisa (1980), but differs from that genus in lacking a

prominent spine to the frontal lobe; instead it has a median tubercle (spine?)

between the adaxial bifurcations of the 1p furrows. In addition, the glabellar

furrows of Renniella are not connected medially, its 3p furrows do reach the

axial furrows, it possesses prominent axial furrow pits, the occipital furrow is

Ss

Fig. 93. Renniella rossouwi gen. et sp. nov.

A reconstruction of the cephalon based upon PRV-1015.

x 3.

126 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 94. Renniella rossouwi gen. et sp. nov. PRV-1015, an internal mould. Note the isolated

frontal lobe, deep axial furrow pits, distinct tubercle between the adaxial terminations of the 1p

furrows, and the weak adaxial bifurcation of the latter. x 3.

transverse, and the L1 lobes are relatively broader (exsag.) than in Tarijacti-

noides. So far as can be judged, however, the two genera are closely related.

Renniella also bears a superficial resemblance to Bainella gamkaensis

Rennie. It differs from that species in having smaller eyes that are closer to the

axial furrows, 3p furrows joined medially to isolate the frontal lobe, 2p furrows

that are deepest medially and effaced distally, 1p furrows that show a weak

adaxial bifurcation, broader (exsag.) L1 lobes, L2 and L3 lobes that coalesce

distally, and a distinct median tubercle between the adaxial bifurcations of the

1p furrows.

Renniella rossouwi gen. et sp. nov.

Figs 93-94

Material

A single cranidium, PRV-—1015, preserved as an internal mould.

Holotype

The above specimen, PRV-—1015, by monotypy; it is from the main tunnel

at Hex River.

Description

As for diagnosis.

Discussion

The above specimen, although fragmentary, is so distinctive that the writer

has little hesitation in creating a new genus and species to accommodate it.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP WAY

Occurrence

Renniella rossouwi gen. et sp. nov. is currently known only from the

Bokkeveld Group. Its state of preservation suggests the Gydo Formation.

Genus Bainella Rennie, 1930

Type species Bainella bokkeveldensis Rennie, 1930;

by original designation

Discussion

There are unfortunately still nomenclatural problems concerning the gen-

eric names Anchiopella and Bainella (cf. Lespérance & Bourque 1971: 202) and

it is proposed to approach the ICZN (Cooper 1982) to have the former name

formally suppressed in favour of Bainella.

Eldredge & BraniSa (1980) have recently provided an emended diagnosis

and detailed discussion of Bainella to which little can be added. It should be

noted, however, that not all species (e.g. B. africana and B. gamkaensis)

possess a terminal spine to the pygidium, while B. arbuteus (Lake) possesses

variably developed fulcral spines. Moreover, the genal spines of B. africana

(Salter) are situated slightly inside (adaxial) of the genal angles in maturity and

are curved sagittally at their tips. Also, the writer does not personally favour

the use of the term ‘lappets’ for the minute spinules that ornament the pygidial

margins of B. insolita and B. arbuteus and do nothing more than provide the

margin with a scalloped appearance. These are clearly equivalent to the

‘interior denticles’ of Harrington et al. (1959).

Eldredge & BraniSa (1980: 202-203) created the new subgenus Belenops

for Acastoides insolitus Wolfart and Bainella gamkaensis Rennie, diagnosed as

‘.. . species of Bainella with anterior cephalic margin distinctly rounded, and

anterior glabellar lobe greatly inflated. Anterior branch of facial suture tran-

secting a relatively small portion of the anterolateral corner of anterior

glabellar lobe. Glabellar furrows 3p sinuous; 1p glabellar furrows wholly

confluent with axial furrows. Anterolateral region of cephalic doublure sharply

recurved dorsally, confluent with dorsal cephalic surface. Occipital spine gener-

ally present, occasionally absent in some populations. Thorax and pygidium as

for genus.’ While there are obvious similarities when cephalic synapomorphies

are considered, the picture changes somewhat when the pygidial characters of

the various Bainella species are compared. As currently defined, the subgenus

Belenops is of questionable value and it is not used here.

Bainella africana (Salter, 1856)

Figs 33B, 39A-B, S50F, 57A, 58A—D, 66B, 67B, 68A, 70, 76E, 77E, 78A,

95-96, 97B-F, 98B, D, 99A-B, 100.

Phacops (Cryphaeus) africanus Salter, 1856: 218, pl. 25 (figs 1, 3, 5, 8 only).

Phacops africanus Salter, Lake, 1904: 205, pl. 24 (figs 6-8).

Phacops crista-galli (Woodward) Lake, 1904: 205, pl. 24 (fig. 5)).

128 ANNALS OF THE SOUTH AFRICAN MUSEUM

Phacops acacia Schwarz, 1906: 398, pl. 10 (fig. 4).

? Dalmanites (Mesembria) acacia (Schwarz) Clarke, 1913: 116, pl. 5 (figs 5-9).

Phacopidella africana (Salter) Williams & Breger, 1916: 287.

Dalmanites (Anchiopella) africanus (Salter) Reed, 1925a: 122, pl. 8 (fig. 1).

? Dalmanites (Anchiopella) baini Reed, 1925a: 129, pl. 9 (figs 1-3).

Phacops (Phacopina) hiemalis Reed, 1925a: 159, pl. 10 (fig. 8 only).

Bainella? africanus (Salter) Rennie, 1930: 345.

Bainella acacia (Schwarz) Rennie, 1930: 348, pl. 10 (fig. 5), fig. 1.

? Bainella baini (Reed) Rennie, 1930: 345.

Bainella bokkeveldensis Rennie, 1930: 349, pl. 10 (figs 1-4). Struve (in Harrington et ail.),

1959: 0484, fig. 383,2. Eldredge & Ormiston, 1979: 158. Eldredge & BraniSa, 1980: 199,

fig. 3.

? Bainella (Bainella) ‘acacia’ (Clarke) (non Schwarz) Eldredge & Branisa, 1980: 201, figs 2J,

4-5,

Material

The holotype, by lectotype designation herein, BM-—In28608 (Fig. 96),

together with BM-—9857, BM-In23972, 24100, 24102, 28601, 28603, 28605,

28609-28611, 28615, 29235, PRV-57, 92, 292, BPI-i239, SAM-—782, 7179, 7182,

9606, SAM-PDB461, 3076, 3080, 3945, 4222, SMC-A2961, 2962, AM-32,

2124, SU-K434, 461, and RO-22, 30, 48, 193, 221, 223, 708, 710, 749, 756, 764,

779, 784, C75-C76, E14-E36, E53, E75, L18-L19, L59, L74, and P20.

Description

Cephalon. The cephalon is moderately convex, subtrigonal to subpentag-

onal in dorsal outline, and much wider than the sagittal length. The surface is

finely granulose but lacks coarse tuberculation and for all intents and purposes

may be regarded as ‘smooth’. The glabella is slightly convex, distinctly pentag-

onal in outline, and with variable segmentation. The 3p and 2p glabellar

furrows are generally very weak and indistinct; the 3p furrows are directed

anterolaterally, curving forward distally so that they are not confluent with the

axial furrows; the 2p furrows are transverse, perhaps slightly convex to the

anterior and do not reach the axial furrows so that the L2 and L3 lobes coalesce

distally. The 1p furrows are transverse, with deep adaxial, linear apodemal pits

but only weakly connected to the axial furrows. The latter are broad, shallow,

pronounced, almost straight and diverge slightly to the anterior. The occipital

furrow is broadest sagittally with deep linear apodemal pits abaxially behind the

L1 lobes. The posterior border furrows are moderately deep and broad, but

shallow abaxially, and the lateral border furrows are wide, very shallow and

indistinct. There is a very narrow anterior border, with a weak median frontal

process (cf. BPI-i239), separated from the glabella by a very narrow but

distinct preglabellar furrow. The occipital ring is of constant width and bears a

long median spine, and the posterior borders broaden abaxially. The genal

angles are obtusely angulated to subrounded, behind which are prominent,

posteriorly directed spines that are curved adaxially at their distal terminations.

Since these hook-like spines are not a direct continuation of the lateral margins

of the cephalon, they are perhaps best described as metafixigenal spines.

However, in juveniles (Fig. 97D) they are true genal spines and, as such, their

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 129

Fig. 95. Bainella africana (Salter).

A reconstruction based upon the available material.

<1ED:

position changes somewhat during ontogeny. The cheeks are moderately con-

vex, subtrigonal in outline, with the eyes raised on well-developed palpebral

prominences. The eyes are smallish, about one-third of the exsagittal length,

and comprise vertical files of lenses, with 7 ocelli in the central file. There are

distinct anterior ocular ridges that follow the line of the anterior facial sutures

to which they lie immediately adaxial, and are confluent with the anterior

border. The hypostoma is wider than its sagittal length with sharply pointed

anterior wings reflexed vertically. The central body is almost circular, weakly

convex and separated from the posterior and lateral borders by a distinct

groove. The tiny maculae are situated laterally, just posterior to the proximal

130 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 96. Bainella africana (Salter). BM-—In28608, the lectotype and original of

Salter (1856, pl. 25 (fig. 8)), preserved as an internal mould. x 4.

margins of the anterior wings. Border spines are absent from the posterolateral

margins of the hypostoma on the internal mould.

Thorax. The thorax has a rather broad axis, about one-third of the thoracic

width, which tapers slightly to the posterior. The axial rings are very rounded,

constricted sagittally and with long median spines. They broaden distally and

are separated by well-developed ring furrows, the latter with distinct apodemal

pits abaxially. The pleurae are moderately convex, with a fairly distinct ful-

crum; they are divided into prominent anterior and posterior moieties by deep

pleural grooves and are separated by distinct interpleural furrows. Distally the

pleurae bear short, blunt posteriorly directed spines.

Pygidium. The pygidium is moderately convex and subtrigonal in outline,

with a prominent axis tapering posteriorly and terminating in a bluntly rounded

tip. The axis comprises 8—10 rings, about as wide as the ring furrows, and there

is no post-axial field. The first 2-3 ring furrows bear apodemal pits distally, and

the last few rings are indistinct. There are no median tubercles or spines to the

axial rings. The pleural fields are triangular, rather convex, and comprise 5

pairs of pleurae, of which the posterior pair are reduced and insignificant. The

pleurae have deep, broad pleural grooves, and the interpleural furrows are

narrow and indistinct. The pleural grooves do not reach the pygidial margin, so

that there is a narrow, smooth border. Because the lateral margins of the

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 131

pygidium are anteriorly convex and posteriorly concave, this creates the

impression that the axis extends well beyond the posterior margin in some

individuals (Fig. 76E).

Discussion

Regarding Phacops africanus, Reed (1925a: 122) commented that ‘. . . the

primary difficulty in determining the true characters of Ph. africanus of Salter

lies in the uncertain identification of the first specimen figured by Salter under

this name . . . it may be regarded as fairly certain that the poor specimen in the

British Museum, numbered 11295, from Leo Hoek, was the one from which

Salter’s partially restored figure was drawn’. Reed (1925a), however, did not

select a lectotype but regarded Ph. africanus as a recognizable species on the

basis of supplementary topotype material. Rennie (1930: 346) gave a com-

prehensive discussion of Salter’s species and suggested that Lake (1904: 206)

had selected Salter’s (1856, pl. 25 (fig. 1)) first figure ‘. . . as the type figure of

the species, but was unable to recognize in the collections the specimen from

which the figure was taken’. He also refuted Reed’s (1925a) suggestion that

BM-11295 was the original of Salter’s figure 1. Hence Rennie (1930: 347) was

led to conclude that since *... the type has disappeared and the original

description of the species (having been based on several unrelated individuals)

is misleading, Ph. africanus should be considered a nomen dubium, the name

to be retained for Salter’s first figure only’.

Contrary to Rennie’s (1930) suggestion, however, Lake (1904) did not

select a lectotype for Phacops africanus; his exact words were ‘... Salter’s

Phacops africanus appears to include at least four distinct species, and unfortu-

nately the original of his fig. 1 has not yet been recognized with certainty. It

seems, however, to be identical with the specimens here described, and

accordingly I have adopted his name for this form’ (p. 206). Such a statement

cannot be construed as a lectotype designation, and hence Phacops africanus is

still without a holotype. Since the original of Salter’s plate 25 figure 1 cannot be

recognized, either because the figure is composite or the original specimen has

been lost, it is proposed to select as holotype, by formal lectotype designation

herein, the original of Salter’s plate 25, figure 8, BM-—In28608, which formed

part of Salter’s syntype series and is here refigured (Fig. 96).

With the selection of a recognizable lectotype, together with the abun-

dant topotype material now available, it is clear that Bainella acacia

(Schwarz) (Fig. 66B) and B. bokkeveldensis Rennie must become junior sub-

jective synonyms of B. africana (Salter). In addition, the writer has had the

opportunity to study the holotype cephalon, by monotypy, of Phacops (Pha-

copina) hiemalis Reed (1925a: 159, pl. 10 (fig. 8 only)), BM-—In24100. The

occipital ring is damaged (due to the breaking off of the median spine?) and

the genal spines seem to have been broken off. In all other characters. this

specimen agrees with B. africana, of which it is herein considered a junior

subjective synonym.

132 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 97. A. Bainella arbuteus (Lake). Latex cast of an external mould, RO-23. Note the spine

bases to the fulcral axes of the thorax. B—F. Bainella africana (Salter). B. RO-749, an internal

mould. C. SAM-7182, the original of Lake (1904, pl. 24 (fig. 8)), preserved as an internal

mould. D. Latex cast of an external mould, RO-221. Note the shape and position of the genal

spines. E. RO~-710, preserved as an internal mould. F. An unnumbered specimen in the

South African Museum, preserved as an internal mould. G—H. Bainella gamkaensis Rennie.

RO-750, a cephalon retaining cuticle. I-J. Bainella cristagalli (Woodward). I. RO—-790, an

internal mould. J. RO—66, a crushed example retaining cuticle. K. Phacopina? sp. RO speci-

men, preserved as an internal mould. All xX 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 133

Bainella baini (Reed) (1925a: 129, pl. 9 (figs 1-3)) was based upon sev-

eral specimens preserved as dorsoventrally flattened internal moulds in grey-

ish, micaceous sandstone. Since Reed (1925a) had a number of specimens

available to him, it is clear that lectotype designation is required. Conse-

quently, the original of his plate 9, figure 1, SMC-—A2961 (Fig. 100B herein),

is herein selected as lectotype. Reed (1925a: 131) distinguished B. baini from

B. africana in that ‘... the glabella is more pentagonal, the two pairs of

anterior furrows are stronger and deeper, the eyes are larger, and the

ornamentation is much coarser . . . the thoracic segments of D. baini seem to

have shorter, smaller axial spines’. The glabella of the lectotype, however, is

no more pentagonal than many of the topotypes of B. africana now available,

nor do the eyes seem to have been any larger. Moreover, since the length of

the axial spines in B. africana is clearly a function of age, this feature cannot

be used to distinguish B. baini. Indeed, so far as the writer is able to judge,

B. baini differs from B. africana only in possessing relatively deeper 2p and

3p glabellar furrows. Since all material undoubtedly referred to B. africana

represents nodule preservation, whereas the material referred to B. baini is

preserved as crushed sandstone internal moulds, it seems that the differences

may be artefacts of preservation. In any case, Eldredge & BraniSa (1980) have

noted considerable difference in the degree of impression of the 2p and 3p

glabellar furrows of Andinacaste chojnacotensis (Schwarz), and hence the

differences between B. baini and B. africana are of questionable taxonomic

importance. There is also another possibility; the lectotype does not preserve

genal angles and it is also questionable whether a median spine was present

on the occipital ring. The same is also true of a paralectotype, SAM-7786

(Fig. 65B), which also shows weak tuberculation of the frontal lobe more

reminiscent of Kozlowskiaspis ceres (Schwarz). Another paralectotype cepha-

lon of B. baini (Fig. 100A) is extremely poorly preserved; the presence of a

median occipital spine cannot be verified, and there appears to be a short,

straight genal spine that does not curve inward distally as in B. africana. In

the writer’s opinion Dalmanites (Anchiopella) baini Reed is generically inde-

terminate; it may be based upon either or both of Bainella and Kozlowski-

aspis, while the lectotype is probably a synonym of B. africana. It is certainly

a nomen dubium.

Both Reed (1925a) and Rennie (1930) felt that the Dalmanites (Mesem-

bria) acacia (Schwarz) figured by Clarke (1913: 116, pl. 5 (figs 5—9)) did not

precisely agree with their concepts of B. acacia. Eldredge & Branisa

(1980: 201, fig. 4) have recently figured a well-preserved cephalon of Clarke’s

taxon. So far as the writer is able to judge, it differs from B. africana only in

having slightly deeper 2p and 3p furrows (on the cuticular surface) and longer

genal spines that, contrary to the reconstruction of Eldredge & BraniSa (1980),

were probably curved inward distally. The differences are slight and doubtfully

of specific importance but, since this material is in the course of revision by

N. Eldredge, its true taxonomic position will soon be apparent.

ANNALS OF THE SOUTH AFRICAN MUSEUM

134

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135

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

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136 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 100. Bainella cf. africana (Salter). A. SMC-—A2962, syntypes of Dalmanites

(Anchiopella) baini Reed. B. SMC-A2961, a syntype, herein selected as lectotype,

and the original of Reed (1925a, pl. 9 (fig. 1)). All preserved as internal moulds and

all x 1,4.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP Ney

Bainella sanjuanina Baldis (1967: 791, pl. 1 (figs 1-4)) is known only from

cephala that differ from B. africana in having much more deeply impressed 2p

and 3p glabellar furrows, the 3p furrows are distinctly sinuous, and internal

moulds of the frontal lobe show distinct pitting not seen in B. africana. In

addition, the L2 and L3 lobes of B. sanjuanina are more inflated than those of

B. africana. The South American species seems to show a curious admixture of

Bainella and ‘Belenops’ characters; it is certainly specifically distinct from

B. africana and the Malvirn B. ‘acacia’.

Bainella africana lacks the coarse tuberculation of B. arbuteus and B. cris-

tagalli, and is readily separable from B. insolita (Wolfart) and B. gamkaensis on

features of the cephalon and pygidium.

Occurrence

Bainella africana (Salter) is currently known with certainty only from the

Gydo Formation of the Bokkeveld sequence, but it may also be present in the

Fox Bay Beds of the Falkland Islands.

Bainella arbuteus (Lake, 1904)

Figs 5A-B, 44B, 89A, 97A, 101-103, 104A-E, 105B-—C

Phacops arbuteus Lake, 1904: 203, pl. 24 (fig. 2 only).

Dalmanites (Anchiopella) arbuteus (Lake) Reed, 1925a: 128.

? Phacops (Phacopina) hiemalis Reed, 1925a: 159, pl. 9 (fig. 12 only).

Dalmanites arbuteus (Lake) Rennie, 1930: 345.

Non Phacops cf. arbuteus Lake, 1906: 428, pl. 40 (fig. 8).

Material

The holotype, by lectotype designation herein, SAM-7181, the original of

Lake’s (1904) plate 24, figure 2, together with SAM-7178 and perhaps also

SAM-7793, as well as RO23-—24, 298, 707, 785, 805, C72, and BPI-i240.

Description

Cephalon. The cephalon is moderately convex, with a semicircular dorsal

outline, and about twice as wide as the sagittal length. The glabella is pentag-

onal in outline, moderately convex, with broad, shallow axial furrows that

diverge towards the anterior. The entire glabella is coarsely tuberculate, the

tubercles varying considerably in size, but there are characteristically 4 large

tubercles, in buttonhole fashion, between the adaxial terminations of the 3p

glabellar furrows. There is also frequently an enlarged pair of tubercles

between, or close to, the adaxial terminations of the 1p furrows, although these

are somewhat more variably developed. The 3p glabellar furrows are rather

deep, distinctly sinuous, and directed posteromedially at about 70° to the axial

furrows with which they are not connected. The 2p furrows are moderately

deep, anteriorly convex, and directed slightly posteromedially; they do not

connect to the axial furrows. The 1p furrows are subparallel to the 2p furrows,

straight, with deep linear apodemal pits adaxially, and distinctly confluent with

138 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 101. Bainella arbuteus (Lake).

A reconstruction based upon the available material.

x1.

the axial furrows. The occipital furrow is anteriorly convex, broadest sagittally,

and with deep apodemal pits distally. The occipital ring is of uniform width and

bears a prominent median spine, flanked on either side by a small tubercle. The

posterior border furrows are rather deep and well developed, whereas the

lateral border furrows are shallow and ill-defined. The posterior borders

broaden (exsag.) abaxially towards the genal angles that are produced into

subcylindrical genal spines directed diagonally outwards. The cheeks are subtri-

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 139

gonal, moderately convex, with palpebral prominences on which are situated

the eyes. The latter are about one-quarter of the exsagittal length of the

cephalon, with their posterior margins opposite the abaxial terminations of the

lp furrows. The librigenae lack tubercles but there are small, scattered tuber-

cles on the fixigenae, running from the posterior*border furrow forward to

between the eyes and the glabellar axial furrows. The anterior facial sutures do

not transect the lateral margins of the frontal lobe.

Thorax. Although complete thoraxes have not been found, it is certain that

they comprise 11 segments as in all other calmoniids. The axis is moderately

convex, about one-third of the thoracic width, with each ring sagittally con-

stricted and bearing a prominent but rather short median spine, on either side

of which is a small tubercle. The axial rings broaden distally and are separated

by pronounced ring furrows with distal apodemal pits. The pleurae have

distinct fulcra and are divided into anterior and posterior moieties by deep,

rather broad pleural grooves. The pleurae have short, posteriorly directed

distal spines and are separated by well-defined, narrow interpleural grooves. At

the fulcral axis, the posterior moiety of each pleura develops a fulcral spine of

variable prominence, in some individuals almost as long as the axial spines

(Fig. 97A), whereas in others (Fig. 103) they are little more than tubercles.

The posterior moieties are also ornamented with a small tubercle immediately

adaxial to the fulcral spine, as well as 2—4 variably developed tubercles abaxial

to the fulcral spines.

Pygidium. The pygidium is moderately convex, subtrigonal in outline, and

wider than the sagittal length (if the length of the rather prominent post-axial

spine is excluded). The axis is rather broad anteriorly but tapers posteriorly to

terminate rather indistinctly in a bluntly rounded tip. There are 8 distinct axial

rings, narrower than the ring furrows, with a very indistinct ninth ring to the

posterior. On the best-preserved pygidium (Fig. 102C-E), distinct median

tubercles can be seen on the-second, third and fifth rings, while the fourth, sixth

and seventh rings are crenulated by a transverse row of weak, tiny tubercles.

There is a well-developed post-axial field that is extended into a long, subcylin-

drical spine tilted upward (dorsally) somewhat. The pleural fields are rather

convex, subtrigonal in outline and comprise 5 pairs of pleurae, of which the

posterior pair are small and reduced. There are deep, rather broad pleural

grooves and fine, indistinct interpleural furrows. The posterior moieties, which

are thicker and more pronounced than those to the anterior, bear transverse

rows of 2-4 tiny tubercles. The segmentation becomes obsolete distally so as to

leave a more or less smooth border. However, the pygidial margin is marked by

5 pairs of denticles that are situated opposite the pleural ‘ribs’ and give the

margin a scalloped appearance.

Discussion

Rennie (1930) felt that B. arbuteus and B. cristagalli (Woodward) might

have been created for different parts of the same animal. However, material in

ANNALS OF THE SOUTH AFRICAN MUSEUM

140

‘CT x YJOqg pue spjnour jeuJOjUI se paarosoid yiog ~ourds yeuTUtta) [eopuT[Ad

pue sajonuop [eursreur ‘saposaqny [exe AeyNdo1I “yeam dy} SION “867-OU “A-O “LOL-OUW “A-V “(24eT) snamquo

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141

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

[eingyd ay} Jo sjiejap Suimoys “g

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142 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 104. A-E. Bainella arbuteus (Lake). A-C. RO-24. Note the prominent spine bases at the

genal angles. X 1,5. D. RO-805, latex cast of an external mould. x1. E. RO~-805, the

internal mould. x 1. F. Bainella cristagalli (Woodward). RO-160, an unusually large cephalon

preserved as an internal mould. x 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 143

A Es .

Fig. 105. A. Bainella gamkaensis Rennie. RO-67, a relatively complete example retaining

cuticle. B-C. Bainella arbuteus (Lake). Latex casts of external moulds. B. RO-707 (see also

Fig. 102A-B). C. RO-24 (see also Fig. 104A-C). All x 1.

the collection of R. Oosthuizen shows them to be readily separable morpho-

logically although there is a difficult-to-prove possibility that they may be sexual

dimorphs. The available material is certainly inadequate to establish the latter

possibility and it is not pursued further here.

Bainella cristagalli (Woodward) (Fig. 106) differs from B. arbuteus by the

finer, more regular tuberculation of its cephalon, the presence of up to 3

tubercles on either side of the sagittal spines on the axial rings, the absence of

fulcral spines, its smaller size, and the presence of more pronounced median

tubercles and transverse tuberculation to the axial rings of the pygidium of B.

arbuteus.

The specimen figured by Reed (1925a) (Fig. 44B) as perhaps the pygidium

of Phacops (Phacopina) hiemalis seems to be based upon a pygidium of B.

arbuteus that has lost the terminal spine.

Metacryphaeus boulei (Kozlowski) bears a remarkable homoeomorphic

resemblance to this species in features of the cephalon, but lacks axial and

fulcral spines, as well as a terminal spine to the pygidium.

In features of the cephalon, such as sinuous 3p furrows, deeply incised

glabellar segmentation and form of the genal angles, B. sanjuanina Baldis

144 ANNALS OF THE SOUTH AFRICAN MUSEUM

closely approaches B. arbuteus, differing almost solely in having the cephalon

pitted (on the internal mould) rather than tuberculate. Bainella arbuteus is also

allied to B. insolita (Wolfart) in regard to characters of the pygidium and the

possession of short sagittal spines, but the two species are readily separated on

cephalic features.

Occurrence

Bainella arbuteus (Lake) is currently known only from the Gydo Forma-

tion of the Bokkeveld sequence.

Bainella cristagalli (Woodward, 1873)

Figs 5D, 65A, 97I-J, 104F, 106-109

Encrinurus cristagalli Woodward, 1873: 31, pl. 2 (figs 6-7).

Phacops arbuteus Lake, 1904: 203, pl. 24 (fig. 3 only).

Non Phacops crista-galli (Woodward) Lake, 1904: 205, pl. 24 (fig. 5) (= B. africana).

Phacops crista-galli (Woodward) Schwarz, 1906: 392, pl. 10 (fig. 6).

Bainella sp., Rennie, 1930: 354, pl. 9 (fig. 18).

Material

The holotype (Fig. 107), by monotypy, in the British Museum, together

with SAM-7178, 8976, 9606, AM-5, and RO-38, 66, 160, 224, 709, 747, 751,

763, 788-790, 806, C77, and E62.

Description

Cephalon. The cephalon is subtrigonal in dorsal outline, moderately con-

vex, and about twice as wide as the sagittal length. The glabella is moderately

inflated, subpentagonal in outline, with well-marked segmentation and a rhom-

boidal frontal lobe. The axial furrows are broad and shallow and diverge

slightly to the anterior. The 3p furrows are fairly deep, slightly sinuous and

directed posteromedially; the 2p furrows are of similar depth, transverse to

slightly convex anteriorly, and connect weakly with the axial furrows; the Ip

furrows are anteriorly concave, with deep linear apodemal pits adaxially, and

weakly confluent with the axial furrows. The L1 lobes are rather narrow

(exsag.) when compared with the other lobes. The occipital furrow is bowed

forward sagittally, with deep apodemal pits distally. The occipital ring is of

constant width, with a long median spine that distally curves slightly to the

posterior and is flanked on either side by 2-3 small tubercles. The whole of the

glabella is covered with small, apparently randomly distributed, tubercles of

more or less even size. The cheeks are subtrigonal, weakly convex, with the

genal angles produced into stout, diagonally directed spines whose distal

terminations are unknown. The posterior border furrows are rather deep and

well defined, meeting the shallower, indistinct lateral border furrows in acute

angles. The posterior borders broaden (exsag.) towards the genal angles and

carry a transverse row of small tubercles. The rather large eyes, more than

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 145

Fig. 106. Bainella cristagalli (Woodward).

A reconstruction based upon the available material.

X27

one-third of the exsagittal length, are situated on palpebral prominences and

comprise 28-30 vertical files, with up to 8 ocelli per file. There are small,

scattered tubercles both on the fixigenae and librigenae; this tubercle develop-

ment is noteworthy between the eyes and the axial furrows and there is a

transverse row of tubercles on the fixigenae just anterior to the posterior border

furrow.

Thorax. The thorax has a rather broad, moderately convex axis that is

146 ANNALS OF THE SOUTH AFRICAN MUSEUM

about one-third the thoracic width. All axial rings are slightly constricted

sagittally and ornamented with prominent, long median spines; on either side

of the latter on the axial rings are generally 2 prominent tubercles and a

variable number, from 2-5, of smaller tubercles. The ring furrows are promi-

nent, with distal apodemal pits. Each pleura has a distinct fulcrum and a deep

pleural groove that separates a narrow (exsag.) anterior moiety and a promi-

nent, relatively much broader, posterior moiety; the latter is ornamented with a

transverse row of 5—7 small, distinct tubercles.

Pygidium. The pygidium is moderately convex, subtrigonal in dorsal out-

line, and distinctly wider than the sagittal length if the terminal spine is

excluded. The axis is strongly convex, with pronounced axial furrows that

converge only slightly to the posterior, and terminates in an indistinct, bluntly

rounded tip. There are 8 axial rings, much wider than the ring furrows, with the

last ring weak and indistinct in some individuals (Fig. 109). The rings are

ornamented with transverse rows of up to 5 small tubercles that, on RO-790

(Fig. 109), give the sixth and seventh rings a crenulated appearance. The

pleural fields are ornamented with 4 pairs of prominent ribs, each of which

bears a transverse row of up to 5 tubercles, and a weakly developed fifth pair to

the posterior. The ribs become obsolete distally, leaving a narrow, smooth

border which seemingly lacks the marginal denticles of B. arbuteus.

Discussion

Differences from other species of Bainella have been noted above. The

small size and relatively large eyes of B. cristagalli, together with similarities in

Fig. 107. Bainella cristagalli (Woodward). The holotype, by monotypy, and

original of Woodward (1873, pl. 2 (figs 6-7)), which seems to retain cuticle;

housed in the British Museum (Natural History). x 1,5.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 147

glabellar segmentation, tubercle distribution and the form of the genal angles

when compared with B. arbuteus give the writer the impression that one is

dealing here with sexual dimorphs. Since available evidence is insufficient to

establish this, they are treated as morphologically distinct but closely allied

species.

As noted by Rennie (1930), this species closely resembles Malvinella haugi

(Kozlowski) (1923: 51, pl. 2 (figs 11-14); Wolfart 1968: 107, pl. 18 (figs 2-4),

pl. 19, pl. 20 (fig. 1)) in cephalic features, but the Bolivian species lacks axial

Fig. 108. Bainella cristagalli (Woodward). A. RO-747. x1,5. B. RO-788. x 1,6.

C-D. RO-751. 1,4. E-F. RO-38. x 1,6. All preserved as internal moulds.

148 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 109. Bainella cristagalli (Woodward). RO-790, an internal mould. (See also Fig. 971.)

x 5,8.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 149

spines and a terminal spine to the pygidium. Again, the similarities seem to be

due to convergence.

Occurrence

Bainella cristagalli (Woodward) is at present a South African endemic,

known only from the Gydo Formation of the Bokkeveld Group.

Bainella gamkaensis Rennie, 1930

Figs 44C, 87B, 105A, 110-112

? Phacops (Bouleia?) sharpei Reed, 1925a: 161, pl. 9 (fig. 6), pl. 10 (fig. 9).

Bainella gamkaensis Rennie, 1930: 353, pl. 9 (figs 14-17).

Bainella (Belenops) gamkaensis Rennie, Eldredge & Branisa, 1980: 204.

Material

The holotype, SAM-—8977, together with RO-37, 67, 750, 792, 795, C71,

BPI-i248, 250, and questionably the lectotype, designated herein, of

P. (Bouleia?) sharpei Reed, SAM-7794.

Fig. 110. Bainella gamkaensis Renni.

A reconstruction based upon the available material.

<alr

150 ANNALS OF THE SOUTH AFRICAN MUSEUM

Description

Cephalon. The cephalon is much wider than the sagittal length, semicircu-

lar and rather convex. The glabella is expanded forward, with well-defined axial

furrows and an inflated frontal lobe that overhangs the anterior border. There

is a distinct posterior median pit to the frontal lobe but no well-developed

auxiliary impression system. On internal moulds, the 3p furrows are broad

(exsag.), sinuous, almost connecting with the 2p furrows proximally but failing

to unite with the axial furrows. The 2p furrows are also very broad (exsag.),

transverse, and weakly connected to the axial furrows. The 1p furrows are

broad (exsag.), transverse, with deep apodemal pits adaxially, and strongly

connected to the axial furrows. When the cuticle is preserved (Fig. 105A), the

glabellar furrows are somewhat narrower (exsag.) and the 2p and 3p furrows

remain well separated proximally. On internal moulds the L1 lobes are very

narrow (Fig. 111), being very much broader when the cuticle is preserved. The

rather broad occipital furrow, especially on internal moulds, is bowed forwards

slightly sagittally and with deep apodemal pits distally. The occipital ring is of

more or less uniform width and bears a short median spine. The ‘drooping’

cheeks are curved strongly downward, subtrigonal in outline, and with the eyes

elevated on large palpebral prominences. The posterior border furrows are

deeply incised, transverse, while the posterior borders broaden (exsag.) mark-

edly towards the genal angles. The latter are acutely rounded and bear short

genal spines. The lateral border furrows are shallow and indistinct. The eyes

are well separated from the glabella and lie well below the level of the median

glabellar area. The ocelli are arranged in vertical files, but the number of lenses

per row is difficult to ascertain, probably about 8-9 in the central files. As in B.

africana, there are distinct eye ridges. The anterior branches of the facial

sutures do not transect the lateral margins of the frontal lobe, while the

posterior branches pass almost straight outwards to meet the lateral margins

opposite the posterior ends of the eyes. The base of the frontal lobe is

carinate-bisulcate, the upper groove representing a preglabellar furrow and the

lower groove the anterior border furrow. The intervening ridge marks the line

of the rostral suture. On internal moulds the surface of the cephalon is

distinctly granulose, whereas the cuticle (Fig. 44C) is very finely granulose and

prominently dimpled.

Thorax. The thorax of B. gamkaensis cannot readily be distinguished from

that of B. africana although, where observed, the axial spines seem to be

significantly shorter and stubbier. The axial rings are constricted sagittally and

broaden distally, and are separated by deep ring furrows. The axis is about

one-third the thoracic width. The pleural fields are moderately convex, with

deep pleural grooves and well-defined interpleural furrows. The posterior

moiety of each pleura is much broader (exsag.) and more inflated than the

anterior moiety.

Pygidium. The pygidium is almost semicircular in outline, wider than the

sagittal length, and moderately convex. The axis is rather broad anteriorly and

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP Sill

Fig. 111. Bainella gamkaensis Rennie. SAM-8977, the holotype, an in-

ternal mould figured by Rennie (1930, pl. 9 (figs 14-16)). x 1,6.

NS” ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 112. Bainella gamkaensis Rennie. RO-37, a pygidium retaining cuticle. x 6.

tapers to the posterior to terminate in a truncate, indistinct tip a short distance

inside the pygidial margin, leaving a short post-axial field. The axis comprises 7

distinct rings, of which the anterior 3 are narrower than the ring furrows and

bear a well-developed median tubercle. The pleural fields are moderately

convex, subtrigonal in outline, and ornamented with 4 prominent pairs of ribs,

with a very reduced fifth pair to the posterior. The ribs are about as wide as the

intervening grooves and terminate a short distance inside the pygidial margin so

as to leave a narrow, smooth border. The entire surface of the pygidium is

finely granulose.

Discussion

Phacops (Bouleia?) sharpei Reed was based upon isolated pygidia that

compare very favourably with B. gamkaensis except that in the lectotype

(Fig. 87B), preserved as an internal mould, the writer was unable to discern the

small median tubercles on the anterior 3 rings that are found on the exoskele-

ton of B. gamkaensis. While this may merely reflect the different types of

preservation, the writer is loath to replace Rennie’s well-established name by

the poorly known Ph. sharpei, and Reed’s name is herein considered both a

nomen dubium and a nomen oblitum.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 153

As noted by Eldredge & Braniga (1980), the closest relative of B. gamka-

ensis is undoubtedly B. insolita (Wolfart) (1968: 113, pl. 21 (figs 2-3); Eldredge

& Branisa 1980: 204, figs 21, 6-9) which differs in having a less inflated frontal

lobe, less deeply incised 2p and 3p furrows, somewhat smaller eyes, lacks an

anterior border furrow and has a very different pygidium with prominent

post-axial spine and sagittal tubercles on most of the rings. There are also many

more pleurae to the pygidium, which terminate in marginal denticles. In view

of its somewhat older age, there can be no doubt that B. gamkaensis was

descended from B. insolita.

Occurrence

Bainella gamkaensis Rennie is currently recorded only from the Gydo

Formation of the Bokkeveld sequence.

Bainella sp. nov.

Figs 37C-D, 113

Material

PEM-1200B and BPI-1244, both preserved as internal moulds.

Description

Cephalon. The cephalon is known only from specimen PEM-1200B in which

it is not well preserved. Its transverse width was certainly greater than the sagittal

length, probably with a subtrigonal dorsal profile. The glabella is moderately

convex, with prominent axial furrows that diverge slightly to the anterior. The

frontal lobe is rhomboidal but insufficiently well preserved to be certain of the

presence or absence of ornament or an auxiliary impression system. The 3p

furrows are deeply impressed, convex anteromedially, and directed strongly

posteromedially, so as almost to meet sagittally. The 2p furrows are also well

developed, anteriorly convex, and seem to join the axial furrows. The 1p furrows

are very deep, anteriorly concave, and well connected to the axial furrows. L1

broadens (exsag.) distally whilst L2 narrows distally. L3 remains almost constant

in width, perhaps broadening slightly distally. There is no evidence of tubercula-

tion on any of the lobes or on the median area of the glabella. The occipital

furrow is arched strongly forward sagittally and rather shallow, but with deep

apodemal pits distally. The occipital ring is of constant width with the distinct

base of a sagittal spine. The posterior border furrows are deep, subtransverse

and there is a prominent posterior border. The genal angles are acute and might

have tapered into genal spines. The cheeks are strongly downturned, but this

feature is probably mostly due to lateral compression. The poorly preserved eye

base suggests a moderately sized eye, perhaps about one-third of the exsagittal

length of the cephalon. The facial sutures are not preserved.

Thorax. It is very similar to that of B. africana, typically damaged along

the sagittal axis due to the breaking off of the sagittal spines. The ring furrows

have prominent apodemal pits distally. The pleurae show a distinct fulcrum,

154 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 113. Bainella sp. nov. PEM-—1200B, a crushed internal mould.

Note the strongly impressed 2p and 3p furrows, the non-tuberculate

L2 and L3 lobes, and the short terminal spine to the pygidium. x 1.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 55

much enhanced by crushing, with deeply impressed pleural grooves and

weaker, narrower interpleural furrows.

Pygidium. The pygidium of PEM-1200B is poorly preserved. It is rela-

tively rather large, trigonal, and produced posteriorly into a short, mucronate

spine. The strongly convex axis comprises about 10 rings, while the pleural

fields show 5 ribs, narrower than the interspaces, that weaken towards the

seemingly entire border. BPI-i244 may be a well-preserved pygidium of this

species. It is a strongly trigonal pygidium, wider than long (sag.), with a

strongly convex axis comprising 10 rings. The anterior axial rings are narrower

than the ring furrows but after the fourth ring they are broader (sag.) than the

ring furrows. The anterior 3 ring furrows have well-developed apodemal pits

distally. There is no post-axial field, the axial segmentation merely becomes

obsolete and passes into a short, mucronate spine. The pleural fields are

trigonal, strongly downturned, with 4 pairs of pronounced ribs, narrower than

the interspaces, and a very weakly developed fifth pair to the posterior. Each

rib bears a small but distinct node-like tubercle at the fulcrum axis. The ribs

weaken towards the entire margin, becoming effaced just before they reach it.

This specimen seems to retain much of its granular cuticle.

Discussion

There is no other species of Bainella with which the above material may

reasonably be confused. It is closest to B. sanjuanina Baldis (1967: 791, pl. 1

(figs 14)), but the latter species has distinctly sinuous 3p glabellar furrows. It is

clear that the above material represents a new species but, until better pre-

served material is forthcoming, the writer hesitates to name it.

Occurrence

Bainella sp. nov. is known only from the Bokkeveld Group; its state of

preservation suggests the Gydo Formation.

Genus Kozlowskiaspis Branisa & Vanék, 1973

Type species Kozlowskiaspis superna Brani§a & Vanék, 1973,

by original designation

Discussion

Eldredge & Branisa (1980) would recognize two stratigraphically separated

subgenera within Kozlowskiaspis, the younger nominate subgenus and the

older K. (Romanops) (= K. (Romaniella) Eldredge & Branigsa (in Eldredge &

Ormiston 1979), a nomen nudum). Kozlowskiaspis (Romanops) was distin-

guished by its narrower, more highly arched cephalon, narrower frontal lobe,

narrower and more steeply sloping genae, flat cephalic borders that are not

reflected down as in the nominate subgenus, and in pygidial characters. The

latter include 8 (not 9) pairs of pleurae, minute nodes on the pygidial margin

156 ANNALS OF THE SOUTH AFRICAN MUSEUM

adjacent to the anterior 2 pairs of pleurae, a short post-axial field with a less

highly emarginate posterior margin, and a narrower ventral doublure.

Kozlowskiaspis (Kozlowskiaspis) ceres (Schwarz, 1906)

Figs 114-115, 116E

Phacops (Cryphaeus) ceres Schwarz, 1906: 394, pl. 10 (fig. 1).

? Dalmanites (Acastella?) pseudoconvexus Reed, 1925a: 137, pl. 9 (fig. 8).

Dalmanites (Cryphaeus ?) ceres Schwarz, Reed, 1925a: 148.

Dalmanites (Metacryphaeus ?) ceres (Schwarz) Rennie, 1930: 336, pl. 9 (figs 1-2).

Material

The holotype, AM-67, the paratype, AM-—27, together with AM-71,

SAM-PDBS979, 11916, RO-84, and 755, all preserved as internal moulds.

Description

Cephalon. The cephalon is subtrigonal in outline, much wider than the

sagittal length, and only weakly convex. The glabella is distinctly pentagonal,

with weakly impressed, broad, shallow, almost parallel axial furrows and a

rhomboidal frontal lobe. The latter is weakly convex, distinctly marked by the

auxiliary impression system, and extends laterally to in front of the eyes, so that

Fig. 114. Kozlowskiaspis ceres (Schwarz).

A reconstruction based upon the available material.

Ko:

the anterior branches of the facial suture transect the lateral portions of the

frontal lobe. The anterior border is very narrow with a very weak median

rostrum. The 3p furrows are rather shallow, inclined posteromedially at about

50-60° to the axial furrows, and do not seem to connect with the axial furrows,

which they approach very closely. The 2p furrows are transverse, slightly

deeper than the 1p furrows, and distally obsolete so that the L2 and L3 lobes

coalesce abaxially. The 1p furrows are transverse, with deep, linear apodemal

pits and distinctly connected to the axial furrows. There is a weak but distinct

sagittal ridge in AM-—71, behind the frontal lobe. The occipital furrow is arched

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP Sy)

strongly forward, of almost uniform width, and with deep apodemal pits

abaxially. The strong arching of the occipital furrow results in a very significant

broadening of the L1 lobes abaxially. The occipital ring is of constant width and

lacks tuberculation. The cheeks are subtrigonal in outline and slope strongly

downward. The posterior border furrows are deep and transverse, whereas the

lateral border furrows are broad, shallow and indistinct. Anteriorly the border

furrow is obsolete and the short median frontal process is separated from the

glabella by a shallow preglabellar furrow. When preserved, the genal angles are

produced into long, thin, posteriorly directed spines that curve inward distally,

in some individuals at least. The eyes are small, less than one-third of the

exsagittal cephalic length and somewhat elevated on palpebral lobes.

Thorax. Unknown.

Pygidium. On the ventral surface of the paratype cephalon, AM-—27, is the

internal mould of a pygidium unlike any other currently recorded from the

Fig. 115. Kozlowskiaspis ceres (Schwarz). A-B. AM-71. C-E. AM-27, the paratype cepha-

lon with weakly impressed 2p and 3p furrows, and the pygidial fragment preserved on its

reverse side. F. AM-67, the holotype figured by Rennie (1930, pl. 9 (figs 1-2)). Note the

moderately impressed 2p and 3p furrows and the distinct auxiliary impression system. All

preserved as internal moulds and all x 1,7.

158 ANNALS OF THE SOUTH AFRICAN MUSEUM

Bokkeveld sequence. The pygidium is large (macropygous) with a broad,

strongly convex axis that tapers slowly to the posterior so that the axial furrows,

anteriorly at least, are subparallel. The anterior 4 rings are much narrower than

the ring furrows, whereafter the rings and ring furrows are of more or less

equal width (sag.). The posterior part of the axis is not preserved and hence

only 7 axial rings can be counted; the pygidium was certainly significantly

larger. The anterior 2 ring furrows preserve apodemal pits distally. The pleural

fields are not preserved.

Discussion

The Bokkeveld species closely approaches Kozlowskiaspis superna Branisa

& Vanék (1973: 100, pl. 5 (figs 1-7); Eldredge & BraniSa 1980: 260, figs 20,

27-28, 29B). However, the Bolivian species has a relatively broader cephalon

with a subpentagonal outline in dorsal view, slightly larger eyes that are closer

to the glabella, and weak axial furrow pits. It is not known if K. superna

possesses the long genal spines displayed by K. ceres.

Occurrence

Kozlowskiaspis ceres (Schwarz) is at present a South African endemic,

known only from the Gydo Formation.

Genus Deltacephalaspis Eldredge & Branisa, 1980

Type species D. comis Eldredge & BraniSa, 1980;

by original designation

Discussion

This genus was well treated by Eldredge & BraniSa (1980) who distin-

guished two subgenera, the nominate subgenus and D. (Prestalia). The latter

subgenus was separated on the basis of its highly arched cephalon with uptilted

median rostrum, shorter genal spines that arise well to the posterior of the

facial suture, and its downturned cheeks and relatively larger eyes.

Deltacephalaspis pseudoconvexus (Reed, 1925)

Figs 6A, 116A—D

Dalmanites (Acastella?) pseudoconvexus Reed, 1925a: 138, pl. 9 (fig. 9 only).

Material

The cephalon on which Reed (1925a) largely based his description,

KM-419, is lost (P. Beaumont, in /itt. 1980). Consequently, his figured syntype

pygidium, SAM-—7201 (Fig. 6A), is herein selected as lectotype. There are two

other pygidia, SAM-—13295a—b, preserved on the same block, that also belong

here.

159)

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP

saad Sidsp1ysmojzoy “7

‘Tp x “QS67El

-WVS ‘d-0

'6€ X ‘OI6II-NVS ‘(24

‘Tp xX “8C6zeI-NVS 4

eamyas)

-V ‘(psoy) snxaauozopnasd sidspjoydasvyag ‘G-V ‘911 ‘3st

160 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 117. Deltacephalaspis magister Eldredge & Brani§a.

A reconstruction based upon the figured material.

Xx 2.

Description

The pygidium is strongly arched with a smooth, entire border and a

well-developed, cylindrical terminal spine. The axis is weakly convex, broad

anteriorly, and tapers rather rapidly to the posterior. It is bluntly terminated to

the posterior, leaving a distinct post-axial field. Only the anterior 3 axial rings are

well developed but, under good oblique lighting, a further 7 very faint and

indistinct rings can also be discerned. The anterior 2 ring furrows bear apodemal

pits distally. The pleural fields are triangular, weakly convex, sloping, with

pleural segmentation obsolete after the third pair of pleurae. The pleural grooves

are moderately deep and distinct, but become effaced distally to leave a rather

broad, smooth border. The interpleural furrows are faint and indistinct.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 161

Discussion

In the absence of cephala, the subgeneric assignment of D. pseudo-

convexus is unknown. The pygidia of the Bokkeveld species are very close to

those of D. magister Eldredge & Brani§a (1980, fig. 13C-D) (Fig. 117 herein)

but in the absence of more complete Bokkeveld material a detailed comparison

is unwarranted. The pygidia of D. comis Eldredge & Branisa (1980, fig. 11F)

and D. retrospina Eldredge & BraniSa (1980, fig. 11G) possess variably devel-

oped axial tubercles, while the pygidia of species assigned to D. (Prestalia) are

currently unknown.

Occurrence

Deltacephalaspis pseudoconvexus (Reed) is currently known only from the

Gydo Formation of the Bokkeveld Group.

BIOSTRATIGRAPHY

Regional

Conventionally, the base of the Bokkeveld Group is drawn at the base of

the first shale following conformably upon the white, uppermost quartzarenite

of the Table Mountain Group. Theron (1970) envisaged deposition of the

Bokkeveld succession in a shallow embayment open to the sea to the south-

east, and flanked by mature, low-gradient coastal plains. The uniformity of the

lower part of the Bokkeveld sequence, deposited at a time of peak transgres-

sion, contrasts strongly with the variability of the upper part, when major

regression had set in. Consequently, the Bokkeveld sedimentary pile is divided

into a lower Ceres Subgroup and an upper Bidouw Subgroup. Only the Ceres

Subgroup and the Waboomberg Formation, the basal shale of the Bidouw

Subgroup, have yielded marine invertebrates. The following lithostratigraphic

subdivision of the marine part of the sequence has been recognized, from above

downward:

(vii) Waboomberg Formation—fourth shale

(vi) Boplaas Formation—third sandstone

(v) Tra-Tra Formation—third shale

(iv) Hexrivier Formation—second sandstone

(iii) Voorstehoek Formation—second shale

(ii) Gamka Formation—first sandstone

(i) Gydo Formation—first shale

Schwarz (1906) was the first to make a determined effort to recognize a

zonal succession within the Bokkeveld faunas, but without success. He noted,

however, the prevalence of Burmeisteria in the western and northern outcrops

(shallower, quieter waters?), spiriferids in the central region and calmoniid

trilobites in the eastern outcrops. Theron (1972), on the other hand, noted

some broad biostratigraphic subdivisions without doing any detailed palaeonto-

162 ANNALS OF THE SOUTH AFRICAN MUSEUM

logical work; the Ceres Subgroup represents the Australospirifer Range Zone,

the lower-three formations the Burmeisteria Range Zone, the Hexrivier Forma-

tion the Mutationella Range Zone, and the contact horizon with the Table

Mountain Group, between longitudes 20°45’ and 20°15’, a Pleurothyrella Range

Zone. While Theron’s (1972) attempt is admirable, it is clearly unsatisfactory

and any serious biostratigraphic subdivision must await a modern revision of

the invertebrate faunas.

So far as the trilobites are concerned, they are conspicuously rare in the

sandstone units (high energy environments), which are dominated by the

brachiopod Australospirifer hawkinsi (Morris & Sharpe), and hence are largely

confined to the shale units. The vast majority of the trilobites come from the

Gydo Formation, including Bainella africana (Salter), B. arbuteus (Lake), B.

cristagalli (Woodward), B. gamkaensis Rennie, Typhloniscus baini Salter, Ren-

niella rossouwi gen. et sp. nov., Kozlowskiaspis ceres (Schwarz), Pennaia

pupillus (Lake), Oosthuizenella ocellus (Lake), Deltacephalaspis pseudocon-

vexus (Reed), Francovichia clarkei (Ulrich), Ormistoniella malaca (Lake),

Burmeisteria herscheli (Murchison), B. notica (Clarke) and a Metacryphaeus sp.

The only trilobites collected by the writer from the Voorstehoek Formation, or

preserved in the soft greenish shales typical of this unit, are abundant Metacry-

phaeus caffer (Salter) and Burmeisteria herscheli (Murchison), together with

Gamonedaspis boehmi (Knod), Phacopina lakei (Reed) and isolated examples

of Pennaia sp. and Ormistoniella malaca (Lake). Although further collecting

should amplify this list, it is clear that the trilobite faunas of these two units,

and the relative abundance of the constituent species, are substantially differ-

ent. It is proposed, therefore, to term the Gydo Formation the Bainella

africana Assemblage Zone, and the Voorstehoek Formation the Metacryphaeus

caffer Assemblage Zone. The writer has not seen trilobites from the Tra-Tra

Formation, although Theron (1970) records Burmeisteria herscheli (Murchison)

from this unit. The only trilobites so far recorded from the Waboomberg

Formation are frequent Metacryphaeus venustus Wolfart and this unit accord-

ingly becomes the Metacryphaeus venustus Assemblage Zone.

Interregional

The best stacked succession of Malvinokaffric trilobites is to be found in

Bolivia where the following zonation may be recognized, somewhat modified

from Wolfart (1968), from above downwards:

Cryphaeoides rostratus Assemblage Zone

Metacryphaeus tuberculatus Assemblage Zone

Metacryphaeus cornutus Assemblage Zone

Metacryphaeus giganteus Assemblage Zone

Bainella insolita Assemblage Zone

Since the writer would regard Metacryphaeus tuberculatus (Kozlowski) and

M. caffer (Salter) as conspecific, these two zones should be regarded as strictly

coeval and provide a direct biostratigraphic link between Bolivia and South

DEVONIAN TRILOBITA FROM FHE BOKKEVELD GROUP 163

Africa. The general aspect of the faunas from the Bainella africana Assemblage

Zone suggest an age somewhat younger than the B. insolita Assemblage Zone

of Bolivia, as does the presence of Metacryphaeus and Kozlowskiaspis (Koz-

lowskiaspis) in the Gydo Formation. In addition, Francovichia clarkei (Ulrich)

is very closely allied to F. branisi (Wolfart) and, on the basis of the available

evidence, the writer would suggest a correlation of the B. africana Assemblage

Zone with the Bolivian zone of Metacryphaeus giganteus. Metacryphaeus venus-

tus Wolfart is relatively long-ranging, but its relative position in the South

African sequence suggests a correlation with the Bolivian Cryphaeoides rostra-

tus Assemblage Zone.

FAUNAL AFFINITIES

The Malvinokaffric Realm (Fig. 118) was predominant during the late

Emsian and early Eifelian and shows a distinctive fauna characterized by very

rare bryozoans and the absence of reef-building corals, graptolites, conodonts

and goniatites, as well as by the diversity and abundance of calmoniid trilobites

(which are seemingly restricted to this realm), bivalves, and a largely endemic

suite of brachiopods from which atrypids and gypidulids are unknown. The

absence of bedded limestones and reef-building corals, typical of this period in

the Old World Realm, together with the general lack of diversity (at the family

level), leaves little doubt that the Malvinokaffric Realm should be interpreted

as comprising the shallow water, Arctic-type, epicontinental sea that flooded

large areas of Gondwanaland (Clarke 1913; Grabert 1970; House in Middlemiss

et al. 1971).

Antarctica

In this region Devonian strata are encountered in the Ohio Range of the

eastern Horlick Mountains (Doumani et al. in Hadley 1965). Here, marine

sandstones and shales of the Horlick Formation rest nonconformably upon

granitic basement, thus clearly reflecting marine transgression, and have

yielded a fauna that includes the brachiopods Australospirifer, Cryptonella?,

Tanerhynchia, Pleurothyrella, Orbiculoidea, and Lingula, the trilobite Burmeis-

teria, the cricoconarid Tentaculites, and a number of bivalves and gastropods

whose affinities lie with the Bokkeveld and South American faunas. While the

brachiopod faunule displays similar affinities, ‘. . . the absence of key Malvino-

kaffric genera Australocoelia, Scaphiocoelia and Notiochonetes is unexplained’

(Boucot et al. in Hadley 1965: 255). So far as the trilobites are concerned, the

absence of calmoniids is noteworthy, while the ‘Type II’ pygidia of B. antarctica

Saul seem closer to the New Zealand B. expansa (Hector) than to the

Bokkeveld B. herscheli. Indeed, the faunas from the Horlick Formation seem

to have closer links with Tasmania and New Zealand than with South Africa

and, as such, do not support the direct marine link between South Africa and

Antarctica so commonly shown on palaeobiogeographic maps. This provides

164 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 118. Late Emsian-early Eifelian palaeobiogeography to show the extent of the Malvino-

kaffric Realm (M) with respect to the Old World Province. a= Appalachian Subprovince,

K=Cordilleran Subprovince, U=Uralian Subprovince, R= Rhenish Subprovince, stippled

areas = land.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 165

some slight measure of support for the reassembly of Gondwanaland recently

proposed by the writer (Cooper 1980), and it seems likely that migration

between the epicontinental Malvinokaffric Realm and Antarctica occurred via

an Oceanic route the length of the west coast of South America.

As regards the age of the Horlick Formation, it is clearly Devonian but a

more precise age is largely speculative. It seems reasonable, however, to

assume contemporaneity with the Reefton Beds of New Zealand and hence an

Emsian (late?) age.

Bolivia

The trilobite faunas from the Devonian of Bolivia are comparatively well

known following the studies of Ulrich (1892, 1893), Knod (1908), Groth (1912),

Kozlowski (1923), Swartz (1925), Braniga (1960, 1965), Wolfart (1968), Branisa

& Vanék (1973), and Eldredge & BraniSa (1980). As outline above, the

following biostratigraphic subdivisions of the Devonian in Bolivia may be

recognized:

(v) Cryphaeoides rostratus Zone (= lower Sicasica Formation)—with the

genera Cryphaeoides, Metacryphaeus, Phacops (Viaphacops), and

Trimerus (Dipleura)

(iv) Metacryphaeus tuberculatus Zone (= uppermost Belén Formation)—

with Metacryphaeus, Pennaia, Vogesina, and Acanthopyge

(iii) Metacryphaeus cornutus Zone (= low Upper Belén Formation)—with

the trilobites Malimanaspis, Phacops (Viaphacops), Bouleia, Meta-

cryphaeus, Pennaia, Schizostylus, Vogesina, Malvinella, and Acan-

thopyge

(ii) Metacryphaeus giganteus Zone (= upper Lower Belén Formation)—

with Boliviproetus, Phacops (Viaphacops), ‘Australosutura’, Franco-

vichia, Fenestraspis, Chacomurus, Chiarumanipyge, K. (Kozlowski-

aspis), Bouleia, Vogesina, Malvinella, Metacryphaeus, Pennaia, and

Schizostylus ?

(i) Bainella insolita Zone (=lowest Belén Formation and Gamoneda

Formation)—yielding Phacopina, Bainella, Deltacephalaspis (Delta-

cephalaspis), D. (Prestalia), Kozlowskiaspis (Romanops), Pennaia,

Tarijactinoides, Schizostylus (Curuyella), Bouleia, Parabouleia,

Gamonedaspis, Francovichia?, Otarion (Maurotarion), and Burmeis-

teria

As regards the chronostratigraphic correlation of these biostratigraphic

units, it is noteworthy that Phacops (Viaphacops), which first appears in the

M. giganteus Zone, is typically a late Emsian/Eifelian taxon in the Appala-

chians and Siberia (N. Eldredge in litt., 1980). Moreover, the presence of

Trimerus (Dipleura) dekayi (Green) in the Cryphaeoides rostratus Zone, toge-

ther with the brachiopod Pustulatia pustulosa (Hall), allows a direct tie with the

Hamilton Group of the Appalachian Province and hence an Eifelian—Givetian

166 ANNALS OF THE SOUTH AFRICAN MUSEUM

age for this biostratigraphic unit. The correlation with the Bokkeveld faunas

has already been noted.

Brazil

The trilobite faunas of Brazil have been recorded by Hartt & Rathbun

(1875), Katzer (1903), and Clarke (1890, 1913) but are now urgently in need of

modern revision.

The stratigraphy of the Amazonas Basin was discussed by Kr6émmelbein

(1967), who recognized the following succession:

2. Curua Formation

(ii) Xingu Member—gray and greenish, silty, micaceous, or clayey shales

(i) Barreirinha Member—black, fissile, euxinic shales

1. Maecurt Formation

(ii) Ariramba Member—60-400 m of alternating sandstones and silt-

stones with interbedded dark gray, micaceous shales

(i) Jatapu Sandstone—100-400 m of poorly cemented, whitish, fine-

grained quartzarenite with locally interbedded grey to black siltstones

and shales.

The Jatapu Sandstone has yielded abundant trace fossils only, while almost

all the body fossils collected from the Amazon basin, including those described

by Hartt & Rathbun (1875), Clarke (1890), and Katzer (1903), are from the

Ariramba Member. However, according to Kr6mmelbein (1967), the latter unit

may include more than one palaeontological horizon. The latter view is

certainly supported by Krommelbein’s records of Metacryphaeus from this

level, since the trilobite faunas described by Clarke (1890) reveal a very

different aspect to those from the Bokkeveld sequence. The presence of a

peculiar suite of trilobites, dominated by Malvinella-like forms, including

Phacopina braziliensis (Clarke), Pennaia menurus (Clarke), Tarijactinoides

acanthurus (Clarke), Malvinella goeldi (Katzer), ‘Phacops’ (gen. nov. or aff.

Malvinella) scirpeus Clarke, ‘Dalmanites’ (gen. nov. or aff. Malvinella) gemellus

Clarke, ‘D’. (gen. nov. aff. Malvinella) tumilobus Clarke, ‘D’. (gen. nov. aff.

Malvinella) australis Clarke, ‘D’. (gen. nov. aff. Vogesina) galeus Clarke,

‘Phacops’ pullinus Clarke, ‘P’. macropyge Clarke, Metacryphaeus ulrichi (Kat-

zer), M. paituna (Clarke), ‘Dalmanites’ (gen. nov. aff. Fenestraspis) maecurua

Clarke, and ‘D’. infractus Clarke suggests an age close to that of the Bokkeveld

Metacryphaeus caffer Assemblage Zone. Certainly it has a younger aspect than

the faunas of the Gydo Formation.

In the Parana Basin to the south, the Ponta Grossa Shale has yielded

Burmeisteria notica (Clarke), Metacryphaeus australis (Clarke), Pennaia pau-

liana Clarke, Calmonia signifer Clarke, C. micrischia Clarke, C. subsevica

Clarke, Paracalmonia pessulus (Clarke), and Gamonedaspis accola (Clarke).

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 167

The association of Gamonedaspis and Metacryphaeus is a feature of the

Voorstehoek Formation of the Bokkeveld sequence and suggests a correlation

with the Ponta Grossa Shale of Brazil.

Argentina

The Devonian stratigraphy of Argentina has been described by Padula et

al. (1967), while the trilobite faunas have been recorded by Thomas (1905),

Baldis (1967, 1972), Baldis et al. (1976), and Baldis & Longobucco (1977a,

1977b).

In the Argentinian Precordillera, the Talacasto Formation has yielded

Bainella sanjuanina (Baldis 1967), together with Metacryphaeus, ‘Homalono-

tus’, and Trimerus (Padula et al. 1967). The Bainella is closely allied to B.

arbuteus (Lake) and its association with Metacryphaeus suggests a correlation

with the Bainella africana Zone of the Bokkeveld sequence. This is perhaps

also the level of Dalmanitoides drevermanni (Thomas 1905). In the same

region, the somewhat younger Chavela Formation has yielded Phacops chavelai

Baldis & Longobucco, Bouleia dagincourti (Ulrich), Cryphaeoides rostratus

(Kozlowski), Punillaspis argentina (Baldis), and Acanthopyge balliviani (Koz-

lowski). This is a typical Cryphaeoides rostratus Zone faunal assemblage.

Falkland Islands

A Malvinokaffric trilobite fauna is recorded (Clarke 1913) from the Fox

Bay Formation and includes Bainella cf. africana (Salter) (=D. (M.) acacia

Clarke), Oosthuizenella cf. ocellus (Lake), Metacryphaeus falklandicus

(Clarke), Schizostylus? allardyceae (Clarke), and Burmeisteria herscheli (Mur-

chison). The fauna suggests a direct correlation with the B. africana Zone of

the Bokkeveld sequence (Fig. 119).

AGE OF THE BOKKEVELD FAUNAS

Since the Malvinokaffric Realm is characterized by the absence of grapto-

lites, conodonts and goniatites, just these taxa that in the Old World Realm

serve aS prime stratigraphic indicators, the precise age of the Bokkeveld

sequence has been largely a matter for speculation. Thus, Reed (1907) consid-

ered the Bokkeveld faunas to be most closely allied to those from the upper

Lower Devonian (Coblenzian = Siegennian—Emsian) of western Europe and to

the Middle Devonian (Hamiltonian) of North America. Du Toit (1954: 252)

regarded the lower half of the Bokkeveld Group as‘ . . . Lower and probably

late Lower Devonian’, while Theron (1970) suggested the following ages based

upon various invertebrate groups:

brachiopods—Emsian

asteroids—Lower Devonian—Lower Carboniferous

trilobites—Gedinnian (for the Gydo Formation).

ANNALS OF THE SOUTH AFRICAN MUSEUM

168

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phic correlations within the Malvinokaffric Realm.

and biostratigra

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119.

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP 169

On this basis Theron (1970: 201) was led to conclude that the Bokkeveld

sequence was © ... clearly Devonian in age and probably mainly Lower

Devonian’. Boucot & Johnson (in Hallam 1973) considered the brachiopod

faunas of the Ceres Subgroup to indicate, in toto, an Emsian age.

The writer has pointed out elsewhere (Cooper 1977) the importance of

eustatic sea-level changes to chronostratigraphic correlation and thus House’s

(1975) concise resumé of synchronous fluctuations in mean sea-level in the Old

World Realm is of the utmost importance. There can be little doubt that these

fluctuations (Fig. 120) are of eustatic origin and hence of global significance

and, therefore, applicable to the Malvinokaffric Realm. There can also be no

doubt that Bokkeveld sedimentation was initiated by marine transgression (Du

Toit 1954), and that for an epicontinental sea to flood Gondwanaland to the

extent of the Samfrau Sea there must have been a very significant relative rise

in sea-level. It is of the highest significance, therefore, that widespread marine

transgression was initiated only during the late Emsian in the period under

discussion, and that this transgression peaked during the early Eifelian. In the

writer's opinion, therefore, the Bokkeveld sequence cannot be older than late

Emsian and the marine portion should be regarded as of late Emsian—Eifelian

age. This is supported by the suggested correlation of the Bainella africana

Zone with the Bolivian zone of Metacryphaeus giganteus, which was regarded

by Wolfart & Voges (1968) as late Emsian in age. Moreover, as already noted,

this is the level at which Phacops (Viaphacops), typical of the late Emsian—

Eifelian in the Old World Realm, enters the Malvinokaffric succession.

FAMENNIAN

FRASNIAN

GIVETIAN

EMSIAN

SIEGENIAN

GEDINNIAN

Fig. 120. Eustatic fluctuations in sea-level during the Devonian. (Data from House 1975.)

170 ANNALS OF THE SOUTH AFRICAN MUSEUM

SUMMARY

The Bokkeveld trilobite fauna is revised and shown to comprise several

distinct, stratigraphically separated faunal assemblages. The faunas from the

Gydo Formation form the basis for the recognition of the Bainella africana

Assemblage Zone and include the dechenellid Ormistoniella malaca (Lake), the

dalmanitid Francovichia clarkei (Ulrich), the homalonotids Burmeisteria her-

scheli (Murchison) and B. notica (Clarke), together with the calmoniids

Bainella africana (Salter), B. arbuteus (Lake), B. cristagalli (Woodward),

B. gamkaensis (Rennie), Kozlowskiaspis (Kozlowskiaspis) ceres (Schwarz),

Typhloniscus baini (Salter), Pennaia pupillus (Lake), Phacopina cf. padilla

(Eldredge & Branisa), Oosthuizenella ocellus (Lake), Renniella rossouwi gen.

et sp. nov., Deltacephalaspis pseudoconvexus (Reed), and Metacryphaeus sp.

The Metacryphaeus caffer Assemblage Zone is represented by the faunas from

the Voorstehoek Formation. These include abundant Burmeisteria herscheli

(Murchison) and Metacryphaeus caffer (Salter), together with Phacopina lakei

(Reed), Gamonedaspis boehmi (Knod), and rare examples of Ormistoniella

malaca (Lake) and Pennaia sp. The Waboomberg Formation has yielded only

Metacryphaeus venustus Wolfart and is thus accordingly designated the Meta-

cryphaeus venustus Assemblage Zone. In addition to Renniella, two other new

genera are proposed, Ormistoniella and Oosthuizenella, as well as the new

subgenus Metacryphaeus (Wolfartaspis). In addition, Digonus is considered a

junior subjective synonym of Burmeisteria s.s. The suprageneric classification of

the calmoniids is at present unsatisfactory and further work is required. Faunal

affinities and evidence from eustatic changes in sea-level suggest a late Emsian

age for the commencement of Bokkeveld sedimentation, with marine deposi-

tion continuing well into the Eifelian.

ACKNOWLEDGEMENTS

This project was commenced in 1973, while the writer was employed at the

South African Museum, jointly with Dr B. F. Kensley, now of the Smithsonian

Institution, Washington. As Dr Kensley was unable to complete this collabora-

tion, I wish to express my thanks to him for assistance in the field, fruitful

discussion on arthropod taxonomy, and for drawing a number of the recon-

structions.

I am indebted to Mr R. Oosthuizen for making available much of the

material discussed herein, for his thorough reading of the manuscript, and for

his valuable advice derived from a detailed knowledge of the Bokkeveld

trilobites, and to Mr R. Dick of the University of Cape Town who made

available his private collection.

I should like to thank Mr W. Holleman of the Albany Museum for his

assistance and for the loan of Schwarz’s type material; Prof. P. Sdhnge for

access to material in the Geological Collections of the University of Stellen-

bosch; Dr C. L. Forbes of the Sedgewick Museum, Cambridge, for photo-

DEVONIAN TRILOBITA FROM THE BOKKEVELD GROUP I

graphs, latex moulds and information on the Bokkeveld trilobites in his charge;

Dr R. Fortey of the British Museum (Natural History) for photographs of, and

access to, the material in his care; Dr J. N. Theron of the Geological Survey,

Bellville, for access to material collected by him and advice on stratigraphy;

and to Mr P. Beaumont for his efforts to locate the cephalon of Dalmanites

pseudoconvexus. Mr J. van den Heever provided photographs of an example of

Kozlowskiaspis ceres in the South African Museum collections. Dr A. Keyser

of the Geological Survey, Pretoria, and Mr B. Newman of the Port Elizabeth

Museum both gave assistance with the collections in their care, and their help is

gratefully acknowledged.

I am grateful for the ready advice and guidance of Drs H. Alberti, A. J.

Boucot, N. Eldredge, P. Lespérance, A. Ormiston, and R. Wolfart, and their

efforts in supplying me with inaccessible literature. I am especially indebted to

Dr N. Eldredge for his advice, constructive criticism of the manuscript, and for

providing me with photographs of the holotype of Oosthuizenella ocellus

(Lake).

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174 ANNALS OF THE SOUTH AFRICAN MUSEUM

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29:)31-33:

6. SYSTEMATIC papers must conform to the /nternational code of zoological nomenclature

(particularly Articles 22 and 51).

Names of new taxa, combinations, synonyms, etc., when used for the first time, must be

followed by the appropriate Latin (not English) abbreviation, e.g. gen. nov., sp. nov., comb.

nov., Syn. nov., etc.

An author’s name when cited must follow the name of the taxon without intervening

punctuation and not be abbreviated; if the year is added, a comma must separate author’s

name and year. The author’s name (and date, if cited) must be placed in parentheses if a

species or subspecies is transferred from its original genus. The name of a subsequent user of

a 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

scientific names by which the species previously has been designated are listed in chronological

order, with all references to that name following in chronological order, e.g.:

Family Nuculanidae

Nuculana (Lembulus) bicuspidata (Gould, 1845)

Figs 14-15A

Nucula (Leda) bicuspidata Gould, 1845: 37.

Leda plicifera A. Adams, 1856: SO.

Laeda bicuspidata Hanley, 1859: 118, pl. 228 (fig. 73). Sowerby, 1871: pl. 2 (fig. 8a—b).

Nucula largillierti Philippi, 1861: 87.

Leda 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

the year is placed in front of each entry, and the synonym repeated in full for each entry, is

not acceptable.

In describing new species, one specimen must be designated as the holotype; other speci-

mens mentioned in the original description are to be designated paratypes; additional material

not regarded as paratypes should be listed separately. The complete data (registration number,

depository, description of specimen, locality, collector, date) of the holotype and paratypes

must be recorded, e.g.:

Holotype

SAM-—A13535 in the South African Museum, Cape Town. Adult female from mid-tide region, King’s Beach

Port 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.

7. SPECIAL HOUSE RULES

Capital initial letters

(a) The Figures, Maps and Tables of the paper when referred to in the text _

e.g. *... the Figure depicting C. namacolus...’; *. . . in C. namacolus (Fig. 10)...’

(b) The prefixes of prefixed surnames in all languages, when used in the text, if not preceded

by initials or full names

e.g. DuToit but A.L.du Toit; Von Huene but F. von Huene

(c) Scientific names, but not their vernacular derivatives

e.g. Therocephalia, but therocephalian

Punctuation should be loose, omitting all not strictly necessary

Reference 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

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‘Revision of the Crustacea. Part VIII. The Amphipoda.’ :

Specific 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.

Name of new genus or species is not to be included in the title: it should be included in the

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Biological Abstracts.

“WON

3 9088 01206 6817

MICHAEL R. COOPER

A REVISION OF THE DEVONIAN

(EMSIAN-EIFELIAN) TRILOBITA

FROM THE BOKKEVELD GROUP OF

SOUTH AFRICA