The hystricognath rodent Microcavia in the late Pleistocene of Brazil (Rio Grande do Sul, South America) (Mammalia : Caviidae). Biogeographic and paleoenvironmental implications

The first fossil record of the hystricognath genus Microcavia is described for Brazil (Chui creek, Santa Vitoria do Palmar, Rio Grande do Sul State; late Pleistocene, Lagoon-Barrier III System). The specimen studied here consists of an anterior portion of skull, left fragment of mandible and several postcranial bones. Before this record, fossil remains were restricted to the Pleistocene of the Pampean region and Uruguay. Therefore, the presence of Microcavia in southeastern Brazil extends the eastern distribution of the genus in the late Pleistocene of South America. The ecology of living Microcavia species suggests the presence of arid to semiarid microenvironments for that locality.