The genus Offadesma Iredale, 1930 (Bivalvia: Periplomatidae) in the Miocene of Patagonia

• Language: unknown
• Published: 2006
• Subjects: Bivalvia; Periplomatidae; Antarctic; Argentina; New Zealand; Patagonia; The Antarctic; Antarc*
• Online Access: https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00423211_v48_n2_p75_Griffin; https://hdl.handle.net/20.500.12110/paper_00423211_v48_n2_p75_Griffin

The periplomatid genus Offadesma Iredale, 1930 was known from a few species found from the middle Eocene to Recent in New Zealand and Australia. Two new records are added from southern South America in Argentina. Offadesma sp., represented by a sole specimen from the Monte León Formation (late Oligocene-early Miocene) exposed near Santa Cruz, in southern Patagonia, and Offadesma isolatum n. sp., collected at Punta Pardelas (northern Patagonia) in late Miocene rocks referred to the Puerto Madryn Formation. The relationships to other periplomatids from South America seem to be remote, and therefore the migration of Offadesma from Australasia to South America during Cenozoic times as a consequence of the onset of the Antarctic Circumpolar Current is proposed. © CMS, Inc., 2006.