INVESTIGADORES
APESTEGUIA Sebastian
congresos y reuniones científicas
Título:
The tetrapod fauna of La Buitrera, new locality from the basal Late Cretaceous of North Patagonia, Argentina
Autor/es:
SEBASTIÁN APESTEGUÍA; SILVINA DE VALAIS; JORGE A. GONZÁLEZ; PABLO A. GALLINA; FEDERICO L. AGNOLÍN
Lugar:
Bozeman, Montana
Reunión:
Congreso; Annual Meeting of the Society of Vertebrate Paleontology; 2001
Institución organizadora:
Society of Vertebrate Paleontology
Resumen:
In the last three years, a new locality called La Buitrera, 32 km. to the NW of Cerro Policía town (Río Negro Province), in sediments belonging to the Candeleros Formation (Lower Cenomanian), has yielded a diverse fauna of vertebrates. The 2001 field trip provided, for the first time, a faunistic assemblage mainly composed by remains of araripesuchian crocodiles, serpents and the first sphenodontian lepidosaurs from Argentina. The latter were represented by specimens at different ontogenetic stages. All the fossils show evidence of light transportation and subaerial exposure, which along with the presence of paleosols in the same bed suggest periods of environmental stability. The underlying levels provided well preserved and articulated turtles in pelitic facies. These turtles are probably related to those chelids from the neuquenian exposures of the Candeleros Formation, near El Chocón village. Above the level containing the sphenodontian-araripesuchian-serpents assemblage (SAS), there are abundant but disarticulated remains of saurischian dinosaurs and ceratodontid tooth plates (the oldest from Argentina). The lateral continuity of this and its faunal assemblage, has proven to be an useful tool for upgrading stratigraphical relationships. This level is almost continuous between La Piedra Sola, La Buitrera and Quiroga-Montoya localities, distant at least 10 miles among them. More extensive comparisons between the better known and mostly dinosaurian El Chocón fauna and the new La Buitrera fauna will provide data in order to better understand the facial, taphonomical, regional or temporal differences between the Candeleros Formation exposures on both sides of the Limay River.