New Palaeogene metatherians from the Quebrada de Los Colorados Formation at Los Cardones National Park (Salta Province, Argentina)

CHORNOGUBSKY, LAURA; ZIMICZ, A.N.; GOIN, F. J.; FERNICOLA, J.C.; 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, Salta Province, north-western Argentina), is anEocene?Oligocene unit well represented in the Calchaquı Valley area. Here we describe a new metatherian associationrecorded from the base of this formation, inferred as middle Eocene. Represented taxa are: Sparassodonta, family indet.:Patene simpsoni; Polydolopimorphia, Bonapartheriiformes, Argyrolagoidea: family, genus, and species indet.; andBonapartherioidea, Prepidolopidae: Punadolops alonsoi and Coloradolops cardonensis gen. et sp. nov. Patene simpsoni isalso found in the Tonco Valley, near Los Cardones, and at Sao Jose de Itaboraı, Rio de Janeiro, Brazil. Punadolops alonsoiwas originally described from the Geste Formation in Salta and Catamarca provinces. Hitherto, no other Argyrolagoideahave been found in north-western Argentina in the Palaeogene. Coloradolops cardonensis is unique to the locality andlevels here described. The preservation of part of the skull constitutes the best prepidolopid remains known. North-westernArgentina is a key region for the study of the evolution of South American mammals, since it has a singular geographicallocation between the Neotropics and the southernmost part of South America. Due to biogeographical constraints, it maylead to a better comprehension of the continental distribution of metatherian lineages during Cenozoic times.