First fossil record of Bibimys Massoia, 1979 (Rodentia, Cricetidae) from the Early Holocene in Argentina

Abstract

Argentinian fossil records of Bibimys have been well documented in a Late Pleistocene palaeontological site and several Late Holocene archaeological sites in Buenos Aires province. However, the specimen reported here is the first fossil record of this genus from the Early Holocene in Argentina. It was recovered in a fluvial unit dated at 9990 ± 140 yr B.P. from Doll creek, southwestern Entre Ríos province, Argentina. At present, this genus is distributed in the distal area of the Paraná River Delta in the province of Entre Ríos, represented by the species B. torresi, and in the province of Misiones, northern Corrientes, and eastern Chaco and Formosa, represented by the species B. chacoensis. The specimen described here is a contribution to the palaeobiogeography of the genus and to a better understanding of the fossil sigmodontine fauna that inhabited the southwest of the province of Entre Ríos in the recent past.