New caviomorph rodents from the late Oligocene of Salla, Bolivia: taxonomic, chronological, and biogeographic implications for the Deseadan faunas of South America

Caviomorph rodents have been an important component of South American mammal faunas at least since the Oligocene. Those from the Deseadan South American Land Mammal Age (SALMA; late Oligocene) have been exhaustively studied because they are considered key to understanding the evolution of South American rodents. Deseadan faunas are widely distributed from northern Peru to central Patagonia, with those from Salla (Bolivia) and Cabeza Blanca (Argentinean Patagonia) being the most diverse. Recent studies of Deseadan rodents at some localities in high (Cabeza Blanca, Punta Nava, Scarritt Pocket) and low (Contamana) latitudes revealed greater taxonomic diversity. However, at middle latitudes, Salla has not received the same attention, despite being exceptional in terms of the abundance and high-quality preservation of specimens. The aim of this work is to report new caviomorph rodents from Salla, and to discuss their systematic and palaeobiogeographical implications in the context of the South American Deseada...