Pyrisinellidae, a new family of anascan cheilostome bryozoans

A new family of anascan-grade cheilostome bryozoans, Pyrisinellidae n. fam., is introduced, together with two new genera, Pyrisinella n. gen. and Spinisinella n. gen. Containing species previously assigned either to the large, paraphyletic Calloporidae, or Microporidae, pyrisinellids are characterized by having small autozooids with a conspicuous pear-shaped ridge formed by the mural rim and distal rim of the opesia, articulated oral spines, and hyperstomial ovicells recumbent on the distal zooid and indenting its mural rim. Five species of pyrisinellids are described, two of which are new: Spinisinella zagorseki n. gen. et sp., from the Cenomanian or Turonian (Upper Cretaceous) of the Czech Republic, and Setosinella perfluxa n. sp., from the Langhian (Middle Miocene) of Kalimantan, Indonesia. A Recent species, Megapora ringens (Busk), is redescribed and questionably assigned to Pyrisinellidae. Important evolutionary changes within Pyrisinellidae having parallels elsewhere among anascan cheilostomes include: (1) the development of opesiules for passage of the parietal muscles which correlates with a change from a trifoliate to a semielliptical opesia; and (2) the transition from an open spinose ovicell in the oldest species (Spinisinella zagorseki) to a conventional ovicell with a solid hood-like ooecium that characterizes all other species belonging to the family.