Calloporina Neviani, 1895

Berning, Björn, 2012, Taxonomic notes on some Cheilostomata (Bryozoa) from Madeira, Zootaxa 3236, pp. 36-54 : 39-40

Genus Calloporina Neviani, 1895

Calloporina Neviani, 1895: 234 ; Gordon 1984: 104; Zabala & Maluquer 1988: 137; Tilbrook 2006: 213; Zágoršek 2010: 156 (among others).

Type species: Cellepora decorata Reuss, 1847 .

Diagnosis (amended). Colony encrusting. Zooidal frontal shield imperforate apart from a suboral ascopore and lateral areolar pores. Basal pore-chambers large and distinct. Primary orifice semicircular with small condyles in the proximolateral corners, oral spines present. Ovicell hyperstomial, with a completely calcified endooecium separated from a crescentic band of pitted ectooecial calcification by a series of slit-like pseudopores that lead into the intermediate coelomic lumen, ovicell opening not closed by the operculum. Avicularia adventitious with acute mandibles. Ancestrula tatiform with well-developed proximal gymnocyst.

Remarks. The genus Calloporina was introduced for the Miocene Paratethyan species Cellepora decorata Reuss, 1847 , which was considered to be extant, albeit rare, in the Mediterranean Sea and eastern Atlantic. All Calloporina specimens from these regions have been recorded under this name ever since Hincks (1880) reported the species from Madeira (as Microporella decorata ). However, even in the absence of SEM images and precise descriptions, a superficial examination of some of these specimens suggests that, apart from the species introduced here, at least one more species is present today (see below). Nevertheless, the new species still represents one of the very few records of this genus in the northern hemisphere, as most taxa are known from the Southern Hemisphere and particularly from Australasia. The Neogene occurrences in regions as far apart as Japan, Australia and the Paratethys region suggest an evolutionary history of Calloporina reaching back into the Paleogene.

In the most recent generic diagnosis, Gordon (1984: 104) stated that the crescentic exposure in the ooecium is made of endooecium. Judging by the sequence of stages in ooecium formation ( Fig. 10 ), the smooth but pitted crescent may rather be formed by the ectooecium, whereas the endooecium seemingly produces the central part with the rugose surface. However, in order to fully understand its formation and structure, analysis of living specimens is necessary (A. Ostrovsky, pers. comm. 2011).

Figures

FIGURES 6 – 11. Calloporina mariae n. sp. 6, autozooids and ovicellate zooids (paratype, NHMUK 2011.9.1.3). 7, primary orifice; note the corrugated proximal margin (paratype, NHMUK 2011.9.1.3). 8, ovicellate zooids (holotype, NHMUK 2011.9.1.1). 9, ovicell with exposed pitted ectooecium (paratype, NHMUK 2011.9.1.3). 10, zooids at the colony margin with a sequence of ooecium formation (paratype, NHMUK 2011.9.1.3). 11, ancestrula and early astogenetic zooids (on same substratum as holotype but different colony). Scale bars: Fig. 6 = 100 µm; Figs 7, 9 = 40 µm; Figs 8, 10, 11 = 200 µm.