Spinisinella, Martino, Emanuela Di & Taylor, Paul D, 2012

Martino, Emanuela Di & Taylor, Paul D, 2012, Pyrisinellidae, a new family of anascan cheilostome bryozoans, Zootaxa 3534, pp. 1-20 : 6

Genus Spinisinella gen. nov.

Diagnosis. Colony encrusting, multiserial, unilaminar. Autozooids small, distinct, oval, slightly longer than broad, separated by deep furrows. Gymnocyst narrow. Cryptocyst extensively developed, depressed, flat and granular; mural rim salient, together with distal rim of opesia forming pear-shaped border around the cryptocyst and opesia; opesiules lacking. Opesia trifoliate, longer than wide, a pair of rounded indentations present in the proximal third. Oral spines present. Ovicell cribrate, ooecium represented by a pair of spine bases arranged parallel to the long axis of the zooid and bordering a depression on the proximal gymnocyst of the distal zooid. Avicularia and ancestrula not observed.

Type species. Spinisinella zagorseki n. sp.

Etymology. Spini-, in reference to the ovicell ooecium constructed of spines, combined with - sinella, the suffix used for other genera belonging to this family.

Remarks. The spinose ovicell of this new genus is unique for Pyrisinellidae . Ostrovsky & Taylor’s (2005) review of spinose ovicells in cheilostome bryozoans found these primitive ovicells to be present in ten genera belonging to five families of anascan-grade cheilostomes. Of these genera, the zooidal characters of Spinisinella most closely resemble the Cretaceous (and?Paleocene) monoporellid genus Stichomicropora Voigt, 1949 (see also Taylor & McKinney 2002, 2006), especially Stichomicropora sp. 3 of Ostrovsky & Taylor (2005, pp. 329, 331, fig. 8A-C) from the Coniacian of Kent. However, the ovicell spine bases of species of Stichomicropora are aligned transversely to the long axis of the zooids, forming either a straight line or a gently curved arch, whereas those of Spinisinella are arranged parallel to the long axis. In addition, Spinisinella has trifoliate opesia and lacks opesiules, compared with Stichomicropora in which the opesia is semielliptical and opesiules are present in the cryptocyst.

Distribution. Cenomanian or Turonian (Upper Cretaceous).