Posición estratigráfica de los estratos supracretácicos portadores de dinosaurios en Lago Pellegrini, Patagonia septentrional, Argentina

Abstract

We briefly analize the provenance of dinosaur remains and the stratigraphic sequence of the Cretaceous beds cropping out south of the PeIlegrini lake, Rio Negro Province. Fossils are placed in sedimentary deposits belonging to a fluvial system and flood plains. Although originaIly these deposits were interpreted as belonging to the Río Colorado Formation, several authors later missinterpreted the geological setting and referred these beds to the AIlen Formation. In this paper we pro pose that the fauna from PeIlegrini Lake comes from the Río Colorado Formation. Both in Cinco Saltos and in the PeIlegrini lake area the age of the tetrapod beds is regarded as pre-middle Campanian. The fauna includes: dinosaurs (titanosaurs and theropods), boas, turtles and crocodiles.