Tertiary Nuculoids and Arcoids of Eastern Patagonia (Argentina).

DEL RÍO, CLAUDIA JULIA; HORACIO CAMACHO,

PALAEONTOGRAPHICA

E SCHWEIZERBARTSCHE VERLAGS

Lugar: Stuttgart; Año: 1998 vol. ABT. p. 47 - 88

0375-0442

This paper provides the systematic analysis of the marine nuculoids and arcoids bivalves occurring in the late Eocene-late Oligocene strata exposed along the eastern coast of Patagonia (southern South America, Argentina). A sum mary of ages and stratigraphic relationships of the deposits containing this faunas is given, 19 species a re- described and illustrated, and 4 new species and one new subgenus are proposed: Cucullaea (Monteleonia) n.subgn. It is mentioned by the first time for the Tertiary horizons of southern South America the presence of the genera Pseudoportlandia WOODRING, 1925, Lamellinucula SCHENCK, 1944, Sacella WOODRING, 1925, Arca (Eonavicula?) ARKELL, 1929 and Glycymeris (Axinola) HERTLEIN and GRANT, 1972. Moreover, Potiarca IREDALE.1939, Glycymerita FINLAY and MARWICK, 1937 and Glycymeris s.str. DA COSTA, 1778, that had been previously described for the Neogene strata of northern Patagonia (DEL RIO, 1992), are also recognized in older deposits of Patagonia, thus extending their fossil records back to the Eocene of the southwestern Atlantic Ocean.