Eocene Mammals and Continental strata from Patagonia and Antarctic Península

23- GELFO, J.N., REGUERO, M. A., LÓPEZ G. M., CARLINI, A. A., CIANCIO, M. R., CHORNOGUBSKY, L., BOND, M., GOIN, F. J., M. TEJEDOR

Papers on Geology, Vertebrate Paleontology, and Biostratigraphy in Honor of Michael O. Woodburne. L. B. Albright III (ed.). Museum of Northern Arizona Bulletin 64

MUSEUM OF NORTHERN ARIZONA

Lugar: FLAGSTAFF; Año: 2009; p. 567 - 592

ABSTRACT—Mammalian faunal succession in South America is well documented from about 47 to 37 Ma, throughout the Eocene. Most Eocene land mammal-bearing deposits occur in Patagonia and the Antarctic Peninsula basins, and these have been studied by many geologists and paleontologists in the last 20 years. The geology of the San Jorge (eastern Patagonia), “Volcanic-Pyroclastic Complex” (western Patagonia), and James Ross (Antarctic Peninsula) basins are here reviewed and their faunal content analyzed. The temporal assignation of Itaboraian and Riochican South American Land Mammals Ages (SALMAs), usually regarded as late Paleocene, is also discussed. In order to account for the likeness between Eocene faunas, a cluster analysis applying the Simpson coefficient was performed using a data matrix with thirteen faunas and 228 taxa. The faunas represent classic and new localities from Antarctica, Patagonia, Mendoza and central Chile, while the taxa comprise up to three taxonomic categories (genus, family and order) to allow comparison between faunas without common genera. The analysis supports at least three major clusters. The first is formed by western Patagonia (Paso del Sapo localities) plus Antarctica, representing faunas that seem to biochronologically located between the Riochican and Casamayoran SALMAs. The second group is divided between (1) faunas related to the Casamayoran SALMA, and (2) those related to the younger Mustersan SALMA. The latest Eocene – earliest Oligocene faunas are grouped together and represented by three Tinguirirican faunas and a fourth younger fauna which seems to be pre-Deseadan (Oligocene).