NOVEDOSOS MARSUPIALES PALEÓGENOS DE LA FORMACIÓN POZUELOS (GRUPO PASTOS GRANDES) DE LA PUNA, SALTA, ARGENTINA

Abstract

NEW PALEOGENE MARSUPIALS FROM THE POZUELOS FORMATION (PASTOS GRANDES GROUP) EXPOSED IN THE PUNA, SALTA, ARGENTINA. Fragments of two new species of Paleogene masupials were found in the hitherto sterile Pastos Grandes Group (lower part of the Pozuelos Formation) Reigia punae and Prepidolops olonsoi. Reigia punae gen. et sp. nov. represents the first didelphíd Glasbiinae found outside North America (Late Cretaceous). On the other hand, Prepidolops alonsoi sp. nov. is a more advanced bunodontoid species of the recently known South American dídelphoid Prepidolopidae. Because of an undeterminable notoungulate hypsodont cheek-tooth fragment found together with the marsupial remains, the Pozuelos Formation is assigned to the Paleogene, and tentatively correlated to the Patagonían Mustersan (Middle Eocene) or to the central west Argentínían Dívísaderan (Late Eocene). The new Clasbiinae, considered along with the Cretaceous didelphoid found in Southern Perú, suggests a South American origin of the Late Cretaceous of the American marsupials.