The Pleistocene record attributed to the cricetid genus Nectomys (Rodentia, Sigmodontinae): unexpected connections

Abstract

Nectomys is a cricetid genus of medium-large sized oryzomyines broadly distributed in creeks and rivers of lowland South America. It has been mentioned in two localities, one in Bolivia and another in Argentina in Pleistocene assemblages. After revising the fossils that supported both records we conclude that they are not Nectomys. The record from Bolivia is Reigomys primigenus. The record from Argentina is attributable to Scapteromys. In conclusion, past occurrences of Nectomys are restricted to those of undifferentiated Quaternary age from Brazilian caves. The unexpected connections between fossils described here are discussed to explore the rationality behind detected misidentifications.