Microporella ordoides, Martino & Taylor & Gordon, 2020

Martino, Emanuela Di, Taylor, Paul D. & Gordon, Dennis P., 2020, Erect bifoliate species of Microporella (Bryozoa, Cheilostomata), fossil and modern, European Journal of Taxonomy 678, pp. 1-31 : 17-19

Microporella ordoides sp. nov.

urn:lsid:zoobank.org:act:D2F60F45-FFFC-4BA0-9682-FD7CE56CBC64

Fig. 8 ; Table 6

Diagnosis

Colony erect, bifoliate; branches narrow.Autozooids rhomboidal.Frontal shield pustulose, pseudoporous. Orifice semielliptical; hingeline with equal-sized teeth, the outermost smaller; oral spines lacking. Ascopore subcircular, opening horseshoe-shaped coVered by a filigree sieVe plate and a narrow tongue projecting from the distal edge. Avicularium single, placed level with ascopore, oriented distolaterally; crossbar complete; opesia semielliptical; rostrum channeled. Ovicells personate or semipersonate.

Etymology

Referring to its similarity with Microporella ordo Brown, 1952 .

Material examined

Holotype

NEW ZEALAND • Bleached specimen; SE of Campbell Island on the Campbell Plateau; [52°56.4′ S, 169°23′ E]; [159 m]; NZOI St. D35; Recent; NIWA 144883 ( Fig. 8 A–D).

Paratypes (unbleached specimens)

NEW ZEALAND • 1 specimen; SE of Campbell Island on the Campbell Plateau; [53.2333° S, 171.8000° E]; [435 m]; St. F145; Recent; NIWA 119893 ( Fig. 8 E–F) • 1 specimen; SE of Campbell Island on the Campbell Plateau; [53.0917° S, 170.2167° E]; [380 m]; St. F143; Recent; NIWA 144885 (not figured) .

Description

COLONY. Erect, bifoliate; the longest colony observed about 54 mm with the broadest frond about 15 mm, consisting of more than 30 linear series of alternating zooids; growing edge stepped; interzooidal communications not observed.

AUTOZOOIDS. Distinct with interzooidal boundaries marked by narrow grooves, often bordered by salient Vertical walls, rhomboidal, longer than wide (mean L/W = 1.30). Frontal shield conVex, pustulose, the pustules about 20 µm in diameter; marginal areolae usually 6 or fewer, elongate, elliptical to dropshaped, larger at corners of zooids (25–35 µm long by 15 µm wide); non-marginal pseudopores Variable in size (diameter 3–15 µm), numbering oVer 50, arranged semi-regularly.

ORIfICE. Semielliptical, significantly wider than long, hingeline straight or somewhat conVex, with about 17 teeth, equal-sized apart from the outermost few which are smaller; oral spines lacking; folded back transVerse Vertical wall of distal zooid forming a crescent aboVe the distal part of the primary orifice.

ASCOPORE fIELD.As a raised area of gymnocystal calcification at approximately same leVel as orifice but beneath leVel of adjacent frontal shield, located moderately close to orifice hingeline, about 60–70 µm below, separated from it by non-porous cryptocyst with smaller than average pustules; subcircular, 45– 60 µm in diameter, opening horseshoe-shaped, 10–15 × 30–35 µm, coVered by filigree sieVe plate, a narrow, straight tongue usually projecting from the distal edge.

AVICULARIUM. Single, moderately large, present in the majority of autozooids; positioned level with or slightly proximally of ascopore, oriented distolaterally; crossbar complete; opesia semielliptical; rostrum short, teat-shaped, the distal end rounded, distinct channel present. Mandible 160–180 µm long, narrow and pointed.

OVICELLS. Large, bulbous, subglobular or a little longer than wide, personate or semipersonate, proximal arms forming bridge aboVe ascopore; calcification of similar fabric to frontal calcification, continuous with frontal shield of distal zooid; pores small, sparse, mostly located near margins; partly formed oVicells common; orifice of oVicellate zooids hidden in frontal View; secondary orifice of personate ovicells boat-shaped with convex proximal and concave distal edge.

Remarks

This new species is extremely similar to Microporella ordo but differs in a sufficiently large number of characters to justify recognition as a separate species. Colonies of M. ordoides sp. nov. have narrow branches, contrasting with the broad fronds of M. ordo , and the growing edge is stepped rather than smooth. Differences in zooidal morphology include the greater number of pseudopores in the frontal shield of M. ordoides sp. noV., smaller outer teeth on the hingeline of the orifice, a horseshoe-shaped ascopore opening, personate or semi-personate ovicells containing fewer pores, and avicularia tending to be located more proximally than in M. ordo . Specimens of M. ordoides sp. noV. were collected off Campbell Island ( New Zealand) on the Campbell Plateau at a depth of 159– 435 m.

Figures

Fig. 8. Microporella ordoides sp. nov. A–D. Holotype NIWA 144883, Recent, New Zealand. A. Group of zooids at the branch tip. B. Close-up of autozooids. C. Close-up of the orifice, ascopore and adVentitious avicularium. D. Close-up of an autozooid and ovicell. E–F. Paratype NIWA 119893 (unbleached), Recent, New Zealand. Two avicularia with closed and open mandible, respectively. Scale bars: A = 500 µm; B = 200 µm; C–D = 100 µm; E–F = 150 µm.