Resumo

DEL RIO, Claudia J.. The Genus Nodipecten Dall (Bivalvia, Pectinidae) In The Neogene Of Patagonia (Argentina). Ameghiniana [online]. 2006, vol.43, n.4, pp.745-756. ISSN 1851-8044.

The oldest record of the genus Nodipecten Dall is in the late Early Miocene when, according to the fossiliferous record known at present, it had a discontinuous distribution in the western Atlantic Ocean, being recorded in Patagonia and in the Caribbean region. By the end of Middle Miocene time it became extinct in Patagonia and since then remained restricted to the tropical latitudes of the American continent until Recent times, expanding to the eastern tropical Pacific in the Late Miocene. Its association with paratropical taxa in Patagonia points to the development of warm-temperate waters reflecting the Neogene Climatic Optimum. Its extinction in the region and displacement northwards to tropical latitudes followed the abrupt dropping of temperatures by the end of the Middle Miocene. Diagnostic characters for Nodipecten are re-defined in the present paper, this genus is compared with Lyropecten Conrad, and a new endemic species is named: Nodipecten salis nov. sp., which is found in the Chenque Formation (Chubut Province) and in the Gran Bajo del Gualicho Formation (Río Negro Province). It is considered to be diagnostic species of the Nodipecten sp.-Venericor abasolensis-Glycymerita camaronesia Molluscan Assemblage.

Palavras-chave : Tertiary; Miocene; Mollusca; Bivalvia; Pectinidae; Nodipecten; Lyropecten; Patagonia.