THE ALLIGATOROIDEA OF ARGENTINA: AN UPDATE OF ITS FOSSIL RECORD

BONA, P.; BARRIOS F.

Publicación Electrónica de la Asociación Paleontológica Argentina

APA

Año: 2015

The fossil record of Alligatoroidea in Argentina is mainlyrepresented by Caimaninae alligatorids. This lineage recorded two important momentsin its natural history, one at the beginning of the Paleogene (Late Paleocene?MiddleEocene) and the other in the Neogene (Late Miocene). The most ancient record ofalligatoroids in South America comes from the Early Paleocene of Patagonia. It includesbasal forms of caimanines such as Necrosuchusionensis, Eocaiman palaeocenicus, Eocaiman cavernensis, and probably a new species ofalligatoroid, which provide key morphological information on the evolutionary and biogeographic historyof these crocodylians. Anotherimportant moment of the evolutionary history of caimanines is thediversification of the lineage observed during the Miocene. Although there issome isolated cranial material of caimanines from the Late Miocene of northwesternArgentina, the most abundant and diverse fossil Miocene material comes from thenortheast, from a level informally called ?Conglomerado Osífero?. Two genera ofcaimanines are known from this stratigraphic level (Caiman and Mourasuchus)with at least five valid species. Here we present an update of the knowledge of Cenozoic alligatoridsof Argentina, as a tribute to Zulma Gasparini for her invaluable contributionto the understanding of the crocodilian evolution in South America