Revision of Late Paleozoic Pinnid Genera and North American Species of Bivalve Family Pinnidae - BAP #410
This study presents documentation for a revised taxonomy of late Paleozoic pinnid bivalves of North America and some European species relevant to the documentation of North American taxa. Pinnid bivalves are moderately diverse and common in many late
Paleozoic inner continental shelf deposits but are under-represented in fossil collections and remained mostly undocumented until this study began.
Shell characters of late Paleozoic pinnids are tabulated and evidence for prostrate life habit as a recliner during the adult growth stage of some large pinnid species is presented. Some Permian species developed mineralized septation of the anterior portion of the shell. Ten genera are described (7 n. gen.) and 31 species (13 n. sp.) are described, including 2 limited to the type specimen, one designated as nomen dubium with recommendation the name be abandoned, and one is excluded from the Pinnidae. Documentation is presented for the presence of lobe and sulcus structure, in the form of long lobe bands of aragonite on the inner shell surface of smooth-shelled late Paleozoic pinnids. The concept of subterminal beak in late Paleozoic pinnids is dismissed as insignificant and there is no evidence to confirm presence of a duplivincular ligament in late Paleozoic pinnids. The oldest confirmed pinnid species occurrence is in the Boone Formation (Osagean-Meramecian boundary, early Visean) of midcontinent North America.
Thomas E. Yancey
Pages: 90
Issue: BAP 410
Year published: 2024