Megapora Hincks, 1877

Martino, Emanuela Di & Taylor, Paul D, 2012, Pyrisinellidae, a new family of anascan cheilostome bryozoans, Zootaxa 3534, pp. 1-20 : 16

Genus Megapora Hincks, 1877

Revised diagnosis. Colony encrusting, multiserial, unilaminar. Autozooids small, distinct, rounded polygonal or oval, longer than broad, separated by deep furrows. Gymnocyst narrow. Cryptocyst well developed, granular, depressed except for a rounded submarginal ridge. Opesia strongly trifoliate. Oral spines present. Distal pore chamber larger than distolateral pore chambers; pore windows oval. Ancestrula smaller than astogenetically mature autozooids, with gymnocyst absent (or overgrown), an extensive granular cryptocyst, trifoliate opesia and oral spines. Ovicell hyperstomial, prominent; ectooecium with a narrow, median triangular window; distal zooid reduced to small kenozooid. Avicularia absent. Kenozooids often developed around edge of colony.

Type species. Lepralia ringens Busk, 1856 .

Remarks. This cold-water monospecific genus is tentatively assigned to Pyrisinellidae . Although the morphology of the autozooids is closely similar to both Pyrisinella and Spinisinella , the pear-shaped ridge characteristic of pyrisinellids is located inwardly of the mural rim and is formed by a cryptocystal elevation (plus the distal rim of the opesia) rather than being coincident with the mural rim at the boundary between the gymnocyst and the cryptocyst. The taxonomic importance of this difference is unclear. The mural rim in anascans is typically located at the highest point of the frontal wall and is the line along which the frontal membrane is attached to the skeleton. It is conceivable that this attachment migrated outwards during the evolution of Megapora from a conventional pyrisinellid ancestor, causing it to lie outwardly of the highest point on the frontal wall.

Distribution. Recent.