Myriapora, De Blainville, 1830

Zágoršek, Kamil & Gordon, Dennis P., 2014, Revision of the Oligocene bryozoan taxa described by Stoliczka (1862), with the description of a new genus of Bryocryptellidae, Geodiversitas 36 (4), pp. 541-564 : 556

Myriapora Ξ beyrichi ( Stoliczka, 1862) n. comb. ( Fig. 6 G-H)

Cellaria beyrichi Stoliczka, 1862: 83 , pl. 1, fig. 10.

MATERIAL EXAMINED. — Holotype, registered as 1859/0026/0133.

DIAGNOSIS. — Colony multiserial, erect with circular cross section. Branch fragment comprising fewer than 20 autozooecia, these trapezoidal, with densely pseudoporous frontal shields bordered by smooth interzooidal boundaries that represent frontally eroded adjacent zooecial margins. Apertures large, more or less cleithridiate with wedge-shaped sinus delimited by prominent condyles. No avicularia or ooecia.

REMARKS

Ŋe smooth interzooecial boundaries and cleithridiate orifice are distinctive features of this species.Ŋe generic attribution is uncertain in the absence of ovicells and avicularia. Ŋe apertural shape most resembles that seen in Myriapora , a genus confined to Mediterranean and Arctic-Boreal waters, whose species, however, do not normally have such distinct interzooecial boundaries. A species with similarlooking zooecia is Myriapora kuhni Vávra, 2011 , from the Oligocene of Germany; it is encrusting, however, and the visible autozooecial boundaries do not form such a wide outline.

On the other hand, the colonial and zooecial morphology of Stoliczka’s species match that found in Opphiphorina Gordon & d’Hondt, 1997 ( Phorioppniidae ), a monotypic genus known only from New Caledonia and the Kermadec Islands in the Southwest Pacific. Oppiphorina epaxia ( Gordon, 1984) has somewhat cleidridiate apertures (with a broader sinus, however) and densely perforated zooecia with raised margins that, if eroded, would present exactly the smooth interzooecial boundaries seen in C. beyrichi . Similar margins are seen in confamilial Phorioppnia Gordon & d’Hondt, 1997 from New Caledonia, which, however, has non-cleithridiate apertures and dimorphic female orifices. Only the finding of ovicells in Stoliczka’s species will settle the matter.

Figures

FIG. 6. – A-D, Anarthropora macropora (Stoliczka, 1862), n. comb.; A, general view of lectotype; B, autozooecium showing frontal foramina and suboral avicularium; C, syntype showing quincuncial arrangement of autozooecia; D, frontal-shield foramen showing well-preserved radial denticulation;E, F, Escharella grotriani (Stoliczka,1862);E, lectotype showing arrangement of autozooecia; F, zooecium with ooecium and oral spines; G, H, Myriapora? beyrichi (Stoliczka, 1862), n. comb.; G, lectotype showing smooth outlines of autozooecia; H, detail of aperture with condyles typical of myriaporids; I, J, syntype of Eschara porulosa identified as Tubucella mammillaris (Milne Edwards, 1836); I, general view of chosen lectotype of synonymous Eschara porulosa Stoliczka, 1862; J, lateral view of colony showing autozooecia with large apertures. Scale bars: 100 μm.