El género Nodipecten Dall (Bivalvia, Pectinidae) en el Neógeno de la Patagonia (Argentina)

DEL RIO, CLAUDIA JULIA

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2006 vol. 43 p. 745 - 756

0002-7014

Abstract - The oldest record of the genus Nodipecten Dall is in the late Early Miocene when, according to the fossiliferous record nown 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.