European Journal of Taxonomy 207: 1-17

http://dx.doi.org/10.5852/ejt.2016.207

This work is licensed under a Creative Commons Attribution 3.0 License.

ISSN 2118-9773

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2016 • Di Martino E. et at.

Research article

urn:lsid:zoobank.org:pub:E16CAFB9-F553-4D91-9761-BBBE4E3B3278

On Powellithecidae fam. nov., a new Pliocene to Recent bryozoan

family endemic to New Zealand, with the description

of Powellitheca gen. nov. (Bryozoa, Cheilostomata)

Emanuela DI MARTINO 1 *, Paul D. TAYLOR 2 , Dennis P. GORDON 3 & Lee Hsiang LIOW 4 - 5

'^Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK.

’National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand.

4 Centre for Ecological and Evolutionary Synthesis, Department of Biosciences,

University of Oslo, Oslo, Norway.

^Natural History Museum, University of Oslo, Oslo, Norway

* Corresponding author: [email protected]

2 Email: p.tavlor@nhm ac uk

3 Email: dennis [email protected]

4 Email: [email protected]

1 um:lsid:zoobank.org:author:A7905C48-FF37-4D27-BCCE-F0560AF040A2

2 um:lsid:zoobank.org:author:7AFF2929-DF5B-46B2-94E6-B26B396CC2C8

3 urn:lsid:zoobank.org:author:DD9C0F3A-8512-4AC8-B395-7687CE3FC565

4 um:lsid:zoobank.org:author:9A708FAA-486A-4918-AAC9-AF7795F3B675

Abstract. A new cheilostome bryozoan genus, Powellitheca gen. nov., is erected here for three species

from New Zealand, one of which has been previously assigned to Emballotheca Levinsen, 1909, but

which differ significantly from the Australian type species of Emballotheca , E. quadrata (MacGillivray,

1880). Notably, whereas Emballotheca has a cormidial orifice (i.e., formed by numerous neighbouring

zooids), and lepralielliform ooecia, the orifice of Powellitheca gen. nov. is formed by single zooids and

ooecia are of the microporelliform type. The introduction of a new family, Powellithecidae fam. nov.,

becomes necessary because of the nonconformity of Powellitheca gen. nov. with other known families

having microporelliform ooecia. In addition to the Recent type species Powellitheca terranovae gen. et

sp. nov., one other new Recent species, P. labiosa gen. et sp. nov., and a Plio-Pleistocene fossil species,

Monoporella waipukurensis Waters, 1887, are assigned to the new genus.

Keywords. Cheilostomata, Powellithecidae, Plio-Pleistocene, Recent, Wanganui Basin.

Di Martino E., Taylor P.D., Gordon D.P. & Liow L.H. 2016. On Powellithecidae fam. nov., a new Pliocene to

Recent bryozoan family endemic to New Zealand, with the description of Powellitheca gen. nov. (Bryozoa,

Cheilostomata). European Journal of Taxonomy 207: 1-17. http://dx.doi.org/10.5852/eit.2016.2Q7

Introduction

Since its first description by Waters (1887) as Monoporella waipukurensis Waters, 1887, the common

New Zealand Plio-Pleistocene species currently known as Emballotheca waipukurensis has caused

European Journal of Taxonomy 207 : 1-17 ( 2016 )

problems for taxonomists, who have placed it in various genera, always with a degree of uncertainty.

Brown (1952) excluded the species from Monoporella Hincks, 1881, as defined by Harmer (1926), but

had difficulties in choosing an alternative genus, thus assigning it to “ HippoporinaT Neviani, 1895,

pending the availability of better material to confirm his identification. Powell (1967) found, for the first

time, several infertile specimens of what seemed to be the same species in Recent material obtained by

the ‘Terra Nova’ Expedition in 1910. He discussed Brown’s tentative assignment of M. waipukurensis

to Hippoporina , noting that the dimorphic orifices, gigantic ooecia and randomly occurring lateral

avicularia were features associated with Emballotheca Levinsen, 1909. Although Powell noted that the

New Zealand species was clearly related to the Australian type species of Emballotheca , E. quadrata

(MacGillivray, 1880), he observed some significant differences between the two taxa in the development

of condyles and the arrangement of avicularia on the fertile zooids, as well as discrepancies among fossil

and modern specimens with regards to the presence/absence of the lyrula and suboral mucro and in the

size of colonies.

Images obtained by Scanning Electron Microscopy (SEM) of a Recent specimen of Emballotheca

quadrata in the Zoological Collection of the Natural History Museum, London (NHMUK) have allowed

us to investigate further the differences between E. quadrata and ostensibly congeneric species from

New Zealand, leading to the introduction of the new genus, Powellitheca gen. nov., for the New Zealand

species. Furthermore, comparison of SEM images of fossil and present-day specimens assigned to

E. waipukurensis confirm the morphological differences first pointed out by Powell (1967). We consider

the dissimilarity to be sufficient to justify the proposal of a new species for Recent material, P. terranovae

gen. et sp. nov., which is chosen as the type species of Powellitheca gen. nov. A second new Recent

species of Powellitheca gen. nov., P. labiosa gen. et sp. nov., is described from northern New Zealand.

As Powellitheca gen. nov. does not conform to any of the other five families with microporelliform

ooecial structure, the new family Powellithecidae fam. nov. is also introduced here.

Material and methods

This study is based on both fossil and Recent material from New Zealand. Fossil specimens of

Powellitheca waipukurensis comb. nov. were collected from the Pleistocene Nukumaru Limestone by

one of us (PDT) in March 1996 at Waiinu Beach, west of Wanganui in the North Island of New Zealand.

Recent material of P. terranovae gen. et sp. nov. was collected on 2 Dec. 1981, using a rock dredge in

Stephens Hole, Cook Strait, at NIWA’s New Zealand Oceanographic Institute (NZOI) Station Q686

(40°41.3' S, 174°03.8' E), at a depth of 205 m. Both fossil and Recent colonies are commonly found

encrusting mollusc or brachiopod shells. Four specimens of the new species P. labiosa gen. et sp. nov.

were collected on 29 Mar. 2011 by epibenthic sled. South Maria ridge, NE of Three Kings Islands, at

NIWA Station TAN1105/53 (33°57.5' S, 17E47.7' E-33°57.6' S, 17U47.6' E), at 107-171 m depth,

as an epibiont of the erect cheilostome bryozoan Malakosaria sinclairii (Busk, 1857), partly wrapping

around the host branch.

The fossil specimens used in this study are deposited in the palaeontological collections of the NHMUK,

while the Recent ones are housed in the NIWA Invertebrate Collection of the National Institute of Water

and Atmospheric Research in Wellington.

For further comparison, a Recent specimen of Emballotheca quadrata (NHMUK 1897.5.1.830) from

Port Phillip Heads (Victoria, Australia) and the lectotype, chosen by Brown (1952), of P. waipukurensis

comb. nov. (NHMUK D32522) from Waipukurau Gorge (?Pliocene), housed in the zoological and in the

palaeontological collections of NHMUK, respectively, were also examined, as was contemporaneous

material (15 colonies) from Hatuma Quarry, near Waipukurau, housed in the NIWA Invertebrate

Collection (NIWA 98228).

DI MARTINO E. et al ., New cheilostome bryozoan Powellitheca

Uncoated specimens were studied and imaged using a LEO 1455VP SEM at the NHMUK and a Hitachi

TM3000 Tabletop SEM at NIWA. Linear measurements were made using optical eyepiece micrometers

and from SEM images using the image processing ImageJ. They are given as the total number of

measurements made (N), mean in microns plus/minus standard deviation (SD), and observed range

( Min and Max).

Measurements are abbreviated as such:

AvL

AvW

OL*

OvL

OvW

OW*

avicularium length

avicularium width

orifice length

orifice length in maternal zooids

ooecium length

ooecium width

orifice width

orifice width in maternal zooids

zooid length

zooid width

Results

Order Cheilostomata Busk, 1852

Superfamily Smittinoidea Levinsen, 1909

Family Powellithecidae fam. nov.

urn:lsid:zoobank.org:act:F43BC913-D3B4-457A-A73C-2B4A5F0897AC

Type genus

Powellitheca gen. nov.

Diagnosis

See genus diagnosis below.

Remarks

Powellithecidae fam. nov. is erected to accommodate the new genus Powellitheca gen. nov., characterised

by a unique suite of morphological characters when compared with all the known families sharing

the same microporelliform ooecial structure. The microporelliform ooecium consists of an uncalcified

ectooecium and a calcified endooecium separated by a narrow coelomic space in communication with

the hypostegal coelom of the distal autozooid, and has been found only in the lepraliomorph families

Microporellidae Hincks, 1879, Pacificincolidae Liu & Liu, 1999, Schizoporellidae Jullien, 1883,

Myriaporidae Gray, 1824 and Porinidae d’Orbigny, 1852 (Ostrovsky 2013). Powellitheca gen. nov.

cannot be accommodated in any of these families. It lacks the ascopore typical of Microporellidae and

the small heterozooid (avicularium or kenozooid) placed between the orifice and the umbo seen in

Pacificincolidae. In Schizoporellidae the orifice has well-defined condyles separating a distinct anter

from a small sinus, while the orifice in Powellitheca gen. nov. is dimorphic, condyles are faint and a sinus

is lacking. An orifice with sinus and condyles also characterises Myriaporidae from which Powellitheca

gen. nov. further differs in having multiporous instead of uniporous septula. Porinidae typically have

erect colonies, a primary orifice with a well-defined sinus, a well-developed aviculiferous peristome,

and a short frontal spiramen.

European Journal of Taxonomy 207 : 1-17 ( 2016 )

Powellitheca gen. nov.

urn:lsid:zoobank.org:act:43B95C9D-F5C5-4802-B508-A952DA9020A6

Type species

Powellitheca terranovae gen. et sp. nov.

Diagnosis

Colony encrusting, with zooids arranged in well-defined longitudinal rows. Zooids with convex,

lepralioid frontal shield, regularly and evenly perforated. Lateral zooidal communication through small

number of multiporous septula in vertical walls. Orifice dimorphic, wider in maternal zooids. Primary

orifice with convex proximal rim and small condyles; not cormidial. Suboral umbo and lyrula present or

absent; oral spines lacking. Ovicells hyperstomial. Ooecia of the microporelliform type, large, globular,

occupying most of the frontal shield of the next distal zooid. Ectooecium uncalcified. Endooecium thick,

granular with deep oval and round pits. Avicularia present or absent, uncommon when present.

Etymology

Named after Neil A. Powell who first described Recent specimens now attributed to this genus in the

‘Terra Nova’ Collection from the Three Kings Islands area, northern tip of New Zealand.

Fig. 1. Emballothecaquadrata (MacGillivray, 1880),NHMUK 1897.5.1.830, Recent, PortPhillip Heads,

Victoria, Australia. A. General view of the colony. B. Autozooidal orifice and avicularia. C. Close-up

of a condyle with scaled tip. D. Fertile zooid and surrounding autozooids. E. Large, spatulate, frontal

avicularium and lateral pore-chamber windows in the vertical walls. Scale bars: A = 500 pm; B = 40 pm;

C = 10 pm; D = 200 pm; E = 100 pm.

DI MARTINO E. et al. , New cheilostome bryozoan Powellitheca

Remarks

The new genus Powellitheca gen. nov. is introduced for three species of cheilostomes from New Zealand,

one of which was previously placed in the Australian genus Emballotheca. After comparing these species

with a specimen of the type species of Emballotheca , E. quadrata (Fig. 1), it is clear that they differ

in several respects, particularly with regard to the morphology of the orifice, ooecium and avicularia.

Although both Emballotheca and Powellitheca gen. nov. have enlarged orifices in maternal zooids and

a similar orificial shape with a convex proximal lip, Powellitheca gen. nov. lacks the cormidial orifice

seen in Emballotheca , as well as the long and robust condyles with very characteristic downwardly

directed, scaled tips (Fig. 1B-C). Ovicells in Emballotheca are hyperstomial and cleithral. The ooecium

is of the lepralielliform type, large, formed by the next distal zooid and occupying its entire frontal

shield. The globular ectooecium is calcified, thick-walled, with numerous oval and round pseudopores,

in most cases covered by the secondary calcification formed by the four or five distal and distolateral

neighboring zooids and separated by thin raised sutures (Fig. 1 A, D). Secondary calcification corresponds

structurally to the zooidal frontal shield and bears pseudopores that are coincident in position with those

of the ectooecium. The endooecium is thin and uncalcified (A. Ostrovsky, pers. comm. 2016). Although

Powellitheca gen. nov. also has hyperstomial ovicells and the ooecium is similarly large and granular,

the ooecia are totally different as they have an uncalcified ectooecium and a calcified endooecium typical

of the microporelliform type.

Avicularia in the type species of Emballotheca have a complete crossbar and are directed proximally

and towards the midline of the autozooid (Fig. IB, D-E), whereas in Powellitheca gen. nov., when

present, they have an incomplete crossbar with short condyles and are distally and outwardly directed.

In E. quadrata , avicularia occur constantly paired in female zooids (Fig. 1A, D), but in Powellitheca

gen. nov. they are unco mm on and less regularly placed. Another difference concerns the arrangement

of zooidal communication pores in the lateral walls, with numerous, small, oval pore chamber windows

in Emballotheca (Fig. IE), but only a few large and consequently more distantly spaced multiporous

septula in Powellitheca gen. nov.

Powellitheca terranovae gen. et sp. nov.

urn:lsid:zoobank.org:act:F8CC3594-F2CB-4E98-945E-800B0C2A460C

Figs 2A-F, 7, Table 1

Emballotheca waipukurensis - Powell 1967: 336, fig. 87. — Gordon 1989: 36, pi. 17, figs E-F. —

Gordon et al. 2009: 291.

Diagnosis

Colony encrusting. Zooids rectangular, arranged in well-defined rows. Frontal shield convex, regularly

and evenly perforated, apart from a narrow peristomial area lacking pores, granular. Small, frontal,

multiporous septula at the distolateral and proximolateral corners of the zooids. Fateral zooidal

communications through multiporous septula visible on the vertical walls. Orifice with a convex proximal

lip and two small, lateroproximally placed condyles, bearing an anvil-shaped median lyrula directed

downwards and not visible in frontal view. Oral spines absent. Ooecium large, globular, occupying

most of the frontal shield of the next distal zooid, porous and granular with the same texture as the

frontal shield. Avicularia uncommon, single or paired, with short condyles and tapered rounded rostrum

distolaterally directed.

Etymology

Named after the ‘Terra Nova’ Expedition, the source of several specimens of this species described

initially by Powell (1967).

European Journal of Taxonomy 207 : 1-17 ( 2016 )

Fig. 2. Powellitheca terranovae gen. et sp. nov. NIWA 98983, Recent, Stephens Hole, NZOI Station

Q686, New Zealand. A. Group of fertile zooids and autozooids. B. Close-up of an autozooid showing

frontal, multiporous septula on the distolateral corners. C. Lateral, multiporous septula on the vertical

walls of a maternal zooid. Note also the prominent, suboral umbo. D. Avicularium. E. Tilted view of an

autozooidal orifice to show the anvil-shaped, downwardly directed lyrula. F. Orifice of a maternal zooid

and incomplete ooecium. Scale bars: A = 250 pm; B-C = 100 pm; D-E = 50 pm; F = 150 pm.

DI MARTINO E. et al.. New cheilostome bryozoan Powellitheca

Table 1. Measurements in microns of Powellitheca terranovae gen. et sp. nov.

N (zooids, colonies)

Mean

Min

Max

20, 1

636

±80

522

824

20, 1

315

±49

233

410

20, 1

126

± 12

111

156

20, 1

167

±8

158

189

OL*

13, 1

223

± 18

200

267

OW*

10, 1

242

±24

179

264

OvL

9, 1

489

±31

444

544

OvW

16, 1

432

±25

400

468

AvL

4, 1

186

± 10

177

198

AvW

4, 1

± 12

Material examined

Holotype

NEW ZEALAND: NIWA 98983, Recent, 2 Dec. 1981, Stephens Hole, Cook Strait, NZOI Station Q686,

40°41.3'S, 174°03.8' E, 205 m.

Description

Colony encrusting, multiserial, unilaminar; colour yellow. Ancestrula not observed. Zooids arranged in

well-defined rows (Fig. 2A), distinct, boundaries marked by very narrow furrows, quadrate to rectangular

generally with squared corners, straight or curved zooidal lateral boundaries, longer than broad (mean

L/W = 2.02). Polypides with 19 tentacles. Frontal shield lepralioid, convex, granular, regularly and

evenly perforated by 50-80 small, circular or slit-like pseudopores about 15-20 pm in diameter (Fig.

2B). Small, rounded triangular, multiporous frontal septula, bearing three or four inconspicuous pores,

about 5-6 pm in diameter, placed at distolateral and proximolateral zooidal corners (Fig. 2B), often

hidden in ovicellate zooids owing to a different surface topography in that area. Orifice placed distally,

generally broader than long, with the proximal rim gently convex and two tiny condyles placed proximal

to the mid-lateral position; an imperforate, granular, slightly raised peristomial rim surrounding the

orifice (Fig. 2E). An anvil-shaped lyrula, placed medially, 60-90 pm broad, occupies about half of

orifice width, directed downwards, vertically or distovertically, and not visible in frontal view (Fig. 2E).

Oral spines and suboral umbo absent. Ovicells hyperstomial. Ooecia globular, large, occupying almost

the entire frontal shield length of the next distal zooid forming the ooecium. Ectooecium uncalcified.

Endooecium thick, granular like the frontal shield but with a finer granulation, with deep oval and round

pits (11-20 pm in diameter) and with a proximal, granular, imperforate band and a narrow, smooth, frontal

rim, slightly upturned (Fig. 2A, C, F). Primary orifice of fertile zooids larger than that of autozooids,

rounded quadrangular, slightly broader than long with a smooth, stout suboral umbo (Fig. 2A, C, F);

secondary orifice slit-like (Fig. 2A). Avicularia uncommon, adventitious, usually single, rarely paired,

lateral to the orifice, on or adjacent to ovicellate zooids, distolaterally directed, with short condyles,

no calcified crossbar, rounded tapered rostrum (Fig. 2D). Oval, multiporous (at least 14 pores) septula

in lateral vertical walls, about 95-120 pm long by 45-55 pm wide (Fig. 2C). Intramural, reparative

budding observed (Fig. 2A).

Remarks

Originally included in the ‘ Emballotheca waipukurensis group’ together with the Plio-Pleistocene

P. waipukurensis comb. nov. (see description below), the Recent specimens now assigned to P. terranovae

European Journal of Taxonomy 207 : 1-17 ( 2016 )

gen. et sp. nov. differ from true P waipukurensis comb. nov. in having an anvil-shaped median lyrula

that is difficult to observe in frontal view because it is directed either vertically downwards or only

slightly distally angled. Further differences are the lack of a suboral umbo in the non-ovicellate zooids

of P. terranovae gen. et sp. nov., a feature that in this species is restricted to the female zooids, and the

different shape of the avicularium rostrum, which is spatulate in P. waipukurensis comb. nov. but distally

tapered and rounded in P. terranovae gen. et sp. nov. They also differ in the size of the zooids, orifice and

ooecia, which are slightly larger in P. terranovae gen. et sp. nov.

Distribution

This species is known from the Cook Strait area and the Three King Islands, from 75 to 205 m depth.

Powellitheca labiosa gen. et sp. nov.

urn:lsid:zoobank.org:act:081F29FC-4C82-4F0D-A537-lAC61EE8E93B

Fig. 3A-F, Table 2

Diagnosis

Colony encrusting. Zooids polygonal, arranged in well-defined rows. Frontal shield markedly convex,

regularly and evenly perforated, smooth. Small, frontal, multiporous septula at the distolateral and

proximolateral zooidal corner. Lateral zooidal communications through small multiporous septula

visible on the vertical walls. Orifice with a weakly convex proximal lip and two small latero-proximally

placed condyles; lyrula and oral spines absent. Primary orifice hidden by a flat, imperforate, finely

granular, projection of the peristome present in both ovicelled zooids and autozooids. Ooecium large,

globular, occupying most of the frontal shield of the next distal zooid, porous and granular. Avicularia

absent.

Etymology

The name of the species derives from the Latin adjective labiosus, -a, -um meaning ‘with a large lip’,

and refers to the flat, labrum-like projection of the peristome covering the primary orifice.

Material examined

Holotype

NEW ZEALAND: NIWA 11828, Recent, 29 Mar. 2011, South Maria ridge, NE of Three King Islands,

NIWA Station TAN1105/53, 33°57.5’S, 17E47.7’ E-33°57.6’ S, 171°47.6’E, 107-171 m.

Paratypes

NEW ZEALAND: NIWA 98229, 98230, same data as for holotype.

Description

Colony encrusting, multiserial, unilaminar (Fig. 3A, D). Maximum colony size about 4 mm long by

2-4 mm wide, fan-shaped. Ancestrula not observed. Zooids arranged in well-defined rows, distinct,

boundaries marked by thin furrows, polygonal, longer than broad (mean L/W = 1.36). Frontal shield

lepralioid, markedly convex, smooth, regularly and evenly perforated by 30—40 small, circular

pseudopores, about 20-35 pm in diameter, sometimes funnel-shaped (Fig. 3C). Small, multiporous

frontal septula, bearing three very small (about 5 pm wide) semicircular pores, placed at distolateral

and proximolateral zooidal corners (Fig. 3C) in both ovicellate and non-ovicellate zooids. Orifice of

autozooids placed distally, generally broader than long, with the proximal lip wealdy convex and two

small, proximolaterally placed condyles (Fig. 3B). A large, flat, imperforate, finely granular, projection

of the peristome hides the orifice in both autozooids and maternal zooids (Fig. 3A); lyrula and oral spines

absent (Fig. 3B). Ovicells hyperstomial. Ooecia globular, large, occupying almost the entire frontal

DI MARTINO E. et al ., New cheilostome bryozoan Powellitheca

Fig. 3. Powellitheca labiosa gen. et sp. nov. NIWA 98320 (A-C, E-F), 98229 (D), Recent, Three King

Islands, New Zealand. A. Group of fertile zooids and autozooids. B. Tilted view of the primary orifice of

an autozooid. Note the lack of a lyrula. C. Close-up of the frontal, multiporous septula on the distolateral

corners and the funnel-shaped pseudopores on the frontal shield. D. Lateral, multiporous septula on

the zooidal vertical walls. E-F. Tilted view of the orifice of fertile zooids. Scale bars: A = 500 pm;

B-C =100 pm; D = 200 pm; E = 250 pm; F = 150 pm.

European Journal of Taxonomy 207 : 1-17 ( 2016 )

Table 2. Measurements in microns of Powellitheca labiosa gen. et sp. nov.

N (zooids, colonies)

Mean

Min

Max

20,4

594

±53

500

722

20,4

438

± 112

311

678

10,4

124

± 16

103

158

17,4

218

±24

170

256

OL*

3,2

218

± 17

200

234

OW*

4,2

269

±21

249

289

OvL

8,2

473

±64

333

533

OvW

8,2

461

±24

443

500

shield of the next distal zooid forming the ooecium. Ectooecium uncalcified. Endooecium granular with

deep oval and round pits that are smaller (15-20 pm in diameter) and more numerous than pseudopores

of the frontal shield (Fig. 3A). Primary orifice of fertile zooids larger than that of autozooids, rounded

quadrangular, slightly broader than long (Fig. 3E-F). Avicularia absent. Multiporous septula small,

about 30-35 pm long by 20-25 pm wide, very distant to each other, bearing two to four tiny pores

visible in lateral vertical walls (Fig. 3D).

Remarks

This species is similar to Powellitheca terranovae gen. et sp. nov. and P. waipukurensis comb. nov. (see

description below) in having a convex, porous frontal shield with small, multiporous frontal septula at the

distolateral and proximolateral zooidal corners (these cannot be seen in studied fossils oTP. waipukurensis

comb, nov.), large, globular, porous and granular ooecia, dimorphic orifices with a convex proximal lip

and tiny proximolateral condyles, and oval, multiporous septula on the vertical lateral walls. It differs

from P. terranovae gen. et sp. nov. and P. waipukurensis comb. nov. (see description below) in having

a well-developed, labrum-like projection of the peristome, and also in having a smooth, non-granular

frontal shield with larger pseudopores. The septula in vertical walls are fewer and much smaller with a

reduced number of pores, circular in P. terranovae gen. et sp. nov., but semicircular in P. labiosa gen. et

sp. nov. In addition, P. labiosa gen. et sp. nov. lacks a lyrula and avicularia.

Distribution

This species is known only from the South Maria ridge, NE of the Three King Islands.

Powellitheca waipukurensis (Waters, 1887) comb. nov.

Figs 4, 5A-D, 6, Table 3

Monoporella waipukurensis Waters, 1887: 50, pi. 6, fig. 11.

Hippoporina? waipukurensis - Brown 1952: 272, figs 203-204.

Emballotheca waipukurensis - Gordon et al. 2009: 296. — Rust & Gordon 2011: 156.

Material examined

Lectotype

NEW ZEAFAND: NHMUK D32522, Mangapanian, ?Pliocene, Hawkes Bay, Waipukurau Gorge.

Additional figured material

NEW ZEALAND: NHMUK BZ 7744 and BZ 7745, Nukumaruan, Pleistocene, Nukumaru Limestone,

Waiinu Beach; NHMUK D36986, same details as lectotype.

DI MARTINO E. et al ., New cheilostome bryozoan Powellitheca

Other material

NEW ZEALAND: NIWA 98228, 15 colonies from Hatuma Quarry, Waipulcurau.

Description

Colony large, encrusting, multiserial, unilaminar (Figs 4, 5A, 6A). Ancestrula minimally calcified,

comprising a thin rim of granular cryptocystal calcification with the outline shaped as a matryoshlca

doll, about 25CM50 pm long by 250-355 pm wide, budding one distal and two distolateral zooids

(Fig. 6D-E). First three budded zooids smaller than later ones, about 230-360 pm long by 240-300

pm wide, hexagonal (Fig. 6D). Zooids developed from ancestrular buds are irregularly polygonal and

Fig. 4. Powellitheca waipukurensis (Waters, 1887) comb. nov. NHMUK BZ 7744, Nukumaruan,

Pleistocene, Nukumaru Limestone, Waiinu Beach. Two colonies of P. waipukurensis encrusting a

bivalve shell, competing with other bryozoan species for space. Note the band of fertile zooids with

large, globular ovicells.

European Journal of Taxonomy 207 : 1-17 ( 2016 )

angled at 90° to 180° to encircle the ancestrula (Fig. 6D). Later autozooids arranged in well-defined

rows, distinct, boundaries marked by very narrow furrows, quadrate to rectangular, generally with

squared corners, longer than broad, with a highly variable length/width ratio (mean L/W = 2.23), some

appearing squat and others slender (Figs 5, 6A-B). Frontal shield lepralioid, slightly convex, granular,

regularly and evenly perforated by 40-50 small, circular pores about 10-15 pm in diameter (Fig. 6A-C).

Frontal septula not distinguishable, probably because of obliteration by the growth of diagenetic cement.

Orifice placed distally, generally broader than long, with the proximal lip gently convex and two tiny

condyles placed proximal to the midlateral position (Fig. 6F); an imperforate, smooth, scarcely raised

peristomial rim lateral and distolateral to the orifice, terminating in a fiat, suboral umbo, palette-shaped,

often broken and leaving an oval depression (Figs 5C-D, 6F). Lyrula and oral spines absent (Fig. 6G).

Ovicells hyperstomial. Ooecia globular, large, occupying almost the entire frontal shield of the next

distal zooid forming the ooecium. Ectooecium membranous. Endooecium calcified, tubercular like the

frontal shield, with deep pits and tubercles radially aligned in alternating ridges and furrows, the frontal

rim imperforate and smooth, slightly upturned (Figs 5A-C, 6C). Primary orifice of fertile zooids larger

than that of autozooids, rounded quadrangular, about as long as wide; secondary orifice slit-like with a

tongue-shaped, suboral umbo (Figs 5A-C, 6C). Avicularia uncommon, adventitious, placed lateral to

the orifice or at zooid midlength, usually single, rarely paired, when paired one smaller, semielliptical

or 8-shaped with a spatulate, rounded rostrum, distolaterally directed (Figs 5C, 6C, F), no crossbar.

Kenozooids budded at junctions between colonies growing on same substratum, similar to autozooids

Fig. 5. Powellitheca waipukurensis (Waters, 1887) comb. nov. Specimen figured by Brown (1952:

fig. 203), NHMUK D36986, Mangapanian, Early Pliocene, Hawkes Bay, Waipukurau Gorge. A. General

view of the colony. B. Group of autozooids and fertile zooids showing the dimorphic orifices. C. Group

of zooids with avicularia. D. Autozooids. Scale bars: A = 500 pm; B-C = 200 pm; D = 100 pm.

DI MARTINO E. et al.. New cheilostome bryozoan Powellitheca

Fig. 6. Powellitheca waipukurensis (Waters, 1887) comb. nov. Nukumaruan, Pleistocene, Nukumaru

Limestone, Waiinu Beach. A-F. NHMUK BZ 7744. A. General view of two colonies encrusting a bivalve

shell. B. Fusion of the two colonies shown in A and formation of kenozooids along the encountering

edge. C. Group of fertile zooids and autozooids. D. Ancestrula and early ontogeny. E. Close-up of the

m inim ally calcified ancestrula. F. Autozooidal orifice and avicularium. — G-H. NHMUK BZ 7745.

G. Internal view of the proximal, convex, orificial rim lacking a lyrula. H. Multiporous septula on the

zooidal vertical walls. Scale bars: A = 1 mm; B = 500 pm; C-D = 200 pm; E-F = 100 pm; G-H = 20 pm.

European Journal of Taxonomy 207 : 1-17 ( 2016 )

Table 3. Measurements in microns of Powellitheca waipukurensis (Waters, 1887) comb. nov.

N (zooids, colonies)

Mean

Min

Max

22,4

562

±50

469

679

22,4

248

±49

182

367

22,4

113

± 11

139

22,4

142

±20

114

182

OL*

12,4

203

± 19

177

203

OW*

12,4

211

± 14

190

211

OvL

40,4

406

±37

339

476

OvW

40,4

354

±38

258

429

AvL

12,4

149

± 17

119

177

AvW

12,4

102

± 12

130

Fig. 7. Powellitheca terranovae gen. et sp. nov. Underwater photograph taken by Dr. Vincent Zintzen

(Department of Conservation, NZ) at the Poor Knights Islands, off the NE coast of North Island, north

of Auckland, New Zealand. Note the band of yellow pigment at the colony’s growing edges and the 19

yellow tentacles of the autozooids.

DI MARTINO E. et al. , New cheilostome bryozoan Powellitheca

in size and in the appearance of the frontal shield but lacking apertures (Fig. 6B). Oval, multiporous (at

least six pores) septula visible on vertical walls (Fig. 6H), about 40 pm long by 20 pm wide. Intramural,

reparative budding also observed (Fig. 6C).

Remarks

Brown (1952: 272, fig. 204) chose NHMUK D32522 from Waipukurau Gorge as the lectotype of this

species. This specimen forms part of the T. Hincks Collection and is accommodated in a cavity slide that

was labelled “ Monoporella waipukurensis on Heteropora [sic]” by Eliza Jelly. Jelly traded bryozoans

extensively in the late 19 th century (Torrens & Winston 2002: 307-308) and the supposition must be that

this particular specimen was used by Waters when describing his new species, then passed on to Jelly

who in turn gave it to Hincks. Brown figured (fig. 203) a fertile specimen (D36986; Fig. 5) from the same

locality and collection to provide details of ooecia, which are lacking in both the lectotype and the Waters’

specimen from Napier housed in the Manchester Museum. Brown (1952, p. 274) questioned the status

of the Manchester Museum specimen, describing it as a slide labelled “ Monoporella waipukurensis ” by

Waters and referring to it as a “?original syntype”. As this specimen lacks ovicells, he considered that it

was not the specimen figured by Waters (1887, pi. 6, fig. 11), which does have ovicells.

Distribution

This species has been found in the Mangapanian Te Aute Fimestone (Pliocene, ~ 3.1 Ma) of Waipukurau

Gorge and nearby Hatuma Quarry, Hawkes Bay, and in the Nukumaruan (early Pleistocene) Nukumaru

Fimestone (~ 2.3-2.0 Ma) and Nukumaru Brown Sand (~ 2.0-1.9 Ma) units of Nukumaru and Waiinu

beaches, Wanganui Basin, and Nukumaruan at Petane (trigonometrical station), just north of Napier,

Hawkes Bay, New Zealand.

Discussion

The continental shelf around New Zealand supports a rich bryozoan fauna estimated to number almost

1000 species (Gordon et al. 2009). Evidence from the fossil record suggests that high diversities of

bryozoans have characterized this region for at least 50 million years (e.g., Gordon & Taylor 2015).

Current research focusing on Plio-Pleistocene bryozoans from the Wanganui Basin has prompted the

re-evaluation of a common cheilostome usually known as Emballotheca waipukurensis (Waters, 1887),

which was originally described from Waipukurau Gorge in Hawkes Bay. Comparison of this species

with the Australian type species of Emballotheca , E. quadrata (MacGillivray, 1880), reveals major

differences in skeletal morphology. In particular, the autozooidal orifice in A quadrata is cormidial, while

the ooecium is of the lepralielliform type, with an uncalcified endooecium and a calcified ectooecium,

covered by the sutured secondary calcification formed by several zooids distal and distolateral of the

fertile zooid. These features contrast with the non-cormidial autozooidal orifice and the microporelliform

ooecial structure of the New Zealand species. Restudy of Recent material from New Zealand previously

identified as Emballotheca waipukurensis shows that it too differs from the Australian type species of

Emballotheca and, although close to the fossils from New Zealand, differs in several respects, warranting

its recognition as a new species. Accordingly, a new genus, Powellitheca gen. nov., is proposed for the

fossil and Recent New Zealand species previously assigned to Emballotheca. Because of the future

possibility of obtaining molecular sequence data from Recent Powellitheca gen. nov. and therefore

placing it in a broader phylogenetic context, P. terranovae gen. et sp. nov. is chosen as the type species

of this new genus in preference to the fossil species P. waipukurensis comb. nov. Another, rarer Recent

species of Powellitheca gen. nov. is also recognized, P. labiosa gen. et sp. nov.

The known distribution of Powellitheca gen. nov. is limited to the North Island of New Zealand and

includes one fossil and two living species. The geologically oldest occurrence is of P. waipukurensis

European Journal of Taxonomy 207 : 1-17 ( 2016 )

comb, nov., which dates back to the Pliocene of Hawkes Bay. This species is common in the Wanganui

Basin until the early Pleistocene, and is a component of a rich and abundant encrusting bryozoan fauna

associated with Ostrea association and Paphies association palaeocommunity shellbeds (Rust & Gordon

2011). These shellbeds are interpreted as deposited mainly in shoreface and inner shelf environments. In

contrast, the two Recent species P. terranovae gen. et sp. nov. and P. labiosa gen. et sp. nov. are found in

deeper water, from 75 to 205 m. The first of these species has a broad distribution, from Cook Strait to

the Three King Islands at the northern tip of New Zealand, while the second species is currently known

only from Three King Islands.

Acknowledgements

We thank the Curator of the Recent Bryozoan Collection Mary Spencer Jones (NHMUK) and the Assistant

Collections Manager Diana Macpherson (NIWA), respectively, for making available specimens of

Emballotheca quadrata and Recent Powellitheca gen. nov. for study, and Consuelo Sendino (NHMUK)

for curating the fossil material. Comments from Andrey Ostrovsky (Saint Petersburg State University

and University of Vienna), Oscar Reverter-Gil (University of Santiago) and an anonymous reviewer

helped to improve the originally submitted manuscript. Specimens of P. labiosa gen. et sp. nov. were

collected as part of the Biogenic Habitats on the Continental Shelf project (voyages TAN1105 &

TAN1108), funded by New Zealand Ministry of Fisheries (Biogenic Habitats: ZBD200801), New

Zealand Foundation for Research, Science and Technology (CCM: CO 1X0907), NIWA Capability Fund

(CF111358), and Oceans Survey 20/20 R/V Tangaroa days funded by Tand Information New Zealand.

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Manuscript received: 17 December 2015

Manuscript accepted: 9 March 2016

Published on: 23 June 2016

Topic editor: Christian de Muizon

Desk editor: Kristiaan Hoedemakers

Printed versions of all papers are also deposited in the libraries of the institutes that are members of the

EJT consortium: Museum national d’Histoire naturelle, Paris, France; Botanic Garden Meise, Belgium;

Royal Museum for Central Africa, Tervuren, Belgium; Natural History Museum, London, United

Kingdom; Royal Belgian Institute of Natural Sciences, Brussels, Belgium; Natural History Museum of

Demnark, Copenhagen, Demnark; Naturalis Biodiversity Center, Leiden, the Netherlands.