Calescharidae, a new family for the tertiary to recent genera Caleschara MacGillivray and Tretosina Canu & Bassler (Bryozoa : Cheilostomata)

Abstract

A new family of Cheilostomata, the Calescharidae, is introduced for the genusCaleschara MacGillivray and its Recent Australian typespecies, C. denticulata(MacGillivray), which isredefined from type and other material. The Australian Tertiary genusTretosina Canu & Bassler and its type species,T. arcifera Canu & Bassler, are closely related,and are also assigned to the Calescharidae. The history and significance offamily attributions of both genera are outlined, and RecentC. denticulata from Australian and other localities isdistinguished from the Late Tertiary Victorian speciesC. parva Maplestone.Caleschara lithconis, sp. nov., from the Late Eocene ofVictoria is one of the earliest known species: its morphology closelyresembles a Recent form from the Philippines,C. junctifera Canu & Bassler. Another Recentspecies, Caleschara minuta (Maplestone) from the GilbertIslands, is a senior synonym of three other Indo-Pacific species,C. levinseni Harmer, C. laxa Canu & Bassler and Floridinella arculifera Canu & Bassler, and resembles the European PaleoceneC. squamosa. Three other related species are brieflydiscussed. Close relationships to other families are problematic and arediscussed; divergence in the early history of the cheilostomes is inferred.