New Paleogene Metatherians from Quebrada de Los Colorados Formation at Los Cardones National Park (Salta Province, Argentina)

CHORNOGUBSKY L; ZIMICZ N; GOIN FJ; FERNICOLA JC; PAYROLA P; CARDENAS M

JOURNAL OF SYSTEMATIC PALAEONTOLOGY

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2019 vol. 17 p. 539 - 555

1477-2019

The Quebrada de Los Colorados Formation (Los Cardones National Park, SaltaProvince, Northwestern Argentina), is an Eocene-Oligocene unit well representedin the Calchaquí Valley area. In this study we describe a new metatherianassociation recorded from the base of Quebrada de los Colorados Formation. Itsinferred age is middle Eocene. Represented taxa are: Sparassodonta, Familyindet.: Patene simpsoni; Polydolopimorphia, Bonapartheriiformes, Argyrolagoidea:family, genus, and species indet.; Bonapartherioidea Prepidolopidae: Punadolopsalonsoi and Coloradolops cardonensis gen. et sp. nov. Patene simpsoni is alsofound in the Tonco Valley, near Los Cardones, and in Sao José de Itaboraí, Rio deJaneiro, Brazil. Punadolops alonsoi was originally described from materials of theGeste Formation at Salta and Catamarca provinces. Up to now, no otherArgyrolagoidea had been found in Northwestern Argentina for the wholePaleogene. Coloradolops cardonensis is unique to the locality and levels heredescribed. The preservation of part of the skull constitutes the best prepidolopidremains found until now. Northwestern Argentina is a key region for the study ofmammalian evolution, since it has a singular geographic location between theNeotropics and South America?s southernmost portion. Due to biogeographicalconstraints, it may lead to a better comprehension of the continental distribution ofmetatherian lineages during Cenozoic times.