Powellitheca waipukurensis Waters 1887, comb. nov.
Creators: name: Emanuela Di Martino
name: Paul D. Taylor
name: Dennis P. Gordon
name: Lee Hsiang Liow
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Bryozoa
Gymnolaemata
Cheilostomatida
Porinidae
Powellitheca
Powellitheca waipukurensis

description: Powellitheca waipukurensis (Waters, 1887) comb. nov.
Figs 4, 5 A–D, 6, Table 3
Monoporella waipukurensis Waters, 1887: 50, pl. 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 ZEALAND: 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.
Other material
NEW ZEALAND: NIWA 98228, 15 colonies from Hatuma Quarry, Waipukurau.
Description
Colony large, encrusting, multiserial, unilaminar (Figs 4, 5 A, 6A). Ancestrula minimally calcified, comprising a thin rim of granular cryptocystal calcification with the outline shaped as a matryoshka doll, about 250–450 μm long by 250–355 μm wide, budding one distal and two distolateral zooids (Fig. 6 D–E). First three budded zooids smaller than later ones, about 230–360 μm long by 240–300 μm wide, hexagonal (Fig. 6 D). Zooids developed from ancestrular buds are irregularly polygonal and angled at 90˚ to 180˚ to encircle the ancestrula (Fig. 6 D). 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, 6 A–B). Frontal shield lepralioid, slightly convex, granular, regularly and evenly perforated by 40–50 small, circular pores about 10–15 μm in diameter (Fig. 6 A–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. 6 F); an imperforate, smooth, scarcely raised peristomial rim lateral and distolateral to the orifice, terminating in a flat, suboral umbo, palette-shaped, often broken and leaving an oval depression (Figs 5 C–D, 6F). Lyrula and oral spines absent (Fig. 6 G). 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 5 A–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 5 A–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 5 C, 6C, F), no crossbar. Kenozooids budded at junctions between colonies growing on same substratum, similar to autozooids in size and in the appearance of the frontal shield but lacking apertures (Fig. 6 B). Oval, multiporous (at least six pores) septula visible on vertical walls (Fig. 6 H), about 40 μm long by 20 μm wide. Intramural, reparative budding also observed (Fig. 6 C).
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 19th 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, pl. 6, fig. 11), which does have ovicells.
Distribution
This species has been found in the Mangapanian Te Aute Limestone (Pliocene, ~ 3.1 Ma) of Waipukurau Gorge and nearby Hatuma Quarry, Hawkes Bay, and in the Nukumaruan (early Pleistocene) Nukumaru Limestone (~ 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.
description: Published as part of Emanuela Di Martino, Paul D. Taylor, Dennis P. Gordon & Lee Hsiang Liow, 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), pp. 1-17 in European Journal of Taxonomy 207 on pages 10-15, DOI: 10.5852/ejt.2016.207, http://zenodo.org/record/269298