Paleogene faunal assemblage from Antofagasta de la Sierra (Catamarca Province, Argentina)

The Paleogene faunal assemblage from Antofagasta de la Sierra (Catamarca, Argentina), is here presented, both in its geological and sistematic aspects. The fossil bearing levels are referred to the Geste Formation (Pastos Grandes Group). The described specimens belong to the Classes Reptilia (Orders Crocodylia, Serpentes and Chelonii) and Mammalia (three taxa from the Superorder Marsupialia, representatives of the Orders Edentata, Condylarthra, Pyrotheria and Astrapotheria, and six families of the Order Notoungulata). This fauna is referred to the Mustersan Age, which in Patagonia represents the Middle Eocene. Such chronologic assignment is based on the presence of characteristic taxa, their evolutionary stage and on stratigraphic evidence. Finally, a brief comparison with other faunal assemblages from the Early Tertiary of Argentina and Chile, is presented.