Setosella antilleana Rosso & Martino & Gerovasileiou, 2020

Rosso, A., Martino, E. Di & Gerovasileiou, V., 2020, Revision of the genus Setosella (Bryozoa: Cheilostomata) with description of new species from deep-waters and submarine caves of the Mediterranean Sea, Zootaxa 4728 (4), pp. 401-442 : 435-437

Woodipora ? antilleana ( Weisbord, 1967) n. comb.

( Fig. 23 )

Setosella antilleana Weisbord, 1967: p. 45 , pl. 8, fig. 1

Examined material. Holotype 14850, Paleontological Research Institution, Ithaca , New York, originally deposited with the catalogue number A684a by Weisbord.

Description. Colony encrusting, unilaminar, forming irregular patches, presumably several mm or even cm wide ( Fig. 23 a–c). Zooidal margins marked by thin furrows. Autozooids quincuncially arranged, roughly rhomboidal, regularly arched distally, reaching the maximum width at about mid-length, and tapering proximally forming a wedge between neighbouring proximal zooids ( Fig. 23d, e ). Zooids with nearly straight or concave proximal margin rare. Gymnocyst only occasionally exposed, forming the surface of the proximal wedges, sometimes producing smooth tubercles ( Fig. 23f ). Cryptocyst coarsely granular, extensive, relatively flat, slightly raised distally to form the proximal border of the opesia and slightly depressed laterally towards the opesiules ( Fig. 23e ). Opesia subelliptical to transversally D-shaped, jagged, slightly wider than long, with maximum width at mid-length and straight to slightly concave proximal border ( Fig. 23d, e ). Spines absent. A pair of elliptical to irregularly shaped opesiules, 8–32 µm long by 3–19 µm wide, placed laterally in the depressed cryptocyst at about zooidal mid-length. Opesiules usually with an arched, slightly crenulated outer side, and a straighter, denticulate inner side. Small interzooidal kenozooids tipically occurring, although inconstantly, at junctions between zooids, triangular to polygonal ( Fig. 23 d–f), with a centrally placed, crenulated, oval to drop-shaped opesia. Additional polygonal kenozooids or interzooidal avicularia, nearly as large as autozooids ( Fig. 23e, g ), with an extensive cryptocyst and a wide circular to elliptical (occasionally elongate eight-shaped), centrally-located opesia, sometimes clustered in presumably peripheral or damaged areas of the colony ( Fig. 23g ). Putative ovicell somewhat prominent, showing a widely exposed, distally sloping plate of coarsely granular cryptocyst, with a large, medially placed, uncalcified window, distal to a transversely elongated prominence lining a possible tubular peristome. Ancestrula not observed. Communications possibly through connecting tubules, placed near the basal surface of lateral walls.

Remarks. Weisbord (1967) placed this species, known only from the type material, in the genus Setosella , but the absence of a vibraculum associated distally to each autozooid dismisses it from the genus. However, the poor preservation of the holotype makes difficult its generic attribution. Available SEM micrographs prevent the observation of some characters hampering the certain inclusion of this species in already established genera or the erection of a new one. Therefore, it is only tentatively referred here to Woodipora Jullien, 1888 , owing to the close resemblance with the type species Woodipora holostoma ( Wood, 1844) from the Pliocene Coralline Crag in England. The autozooids share the general morphology, and have a roundish opesia and widely exposed granular cryptocyst pierced by a pair of very large, lateral opesiules. The large, rare heterozooids with ovoidal to eight-shaped opesia in W.? antilleana are only superficially reminiscent of the elongate interzooidal avicularia typical of the genus. Conversely, the small heterozooids commonly located at the junction between autozooids, a distinctive feature of the present species, were not observed in Woodipora .

Distribution. Woodipora ? antilleana was reported from Cabo Blanco, Distrito Federal, on the Caribbean coast of Venezuela. The species encrusted the shell of a gastropod indicated as Cantharus (Polla) auritum (Lamarck) by Weisbord (1967). The colonies were dead and worn when collected but the colour preserved on the encrusted shell suggests that the species possibly occurred in nearby bottoms.

Ecology. Possibly a shallow-water species.

Figures

FIGURE 23. Woodipora? antilleana (Weisbord, 1967) n. comb. Holotype: 14850, Paleontological Research Institution, Ithaca, New York. a. Gastropod shell encrusted by W.? antilleana with outlines of colonies marked). b. General worn aspect of a colony only partly preserved in furrows between prominent knobs. c. Relatively well-preserved portion of the same colony in (b) occupying a depression. d. Cluster of autozooids and interspersed kenozooids. e. Close-up of the central-upper part in (d). Note some well-preserved autozooids showing their opesiae (short arrows) and large opesiules, and possibly an interzooidal avicularium (long arrow). f. Inclined view to show prominent proximal tubercles. g. Different colony portion with two contiguous large kenozooids or possibly avicularia (arrow). Scale bars: a = 5 mm; b = 1 mm; c, d, f, g = 500 μm; e = 200 μm.