Primer registro fósil del género “oligosarcus” Günther, 1864 (Teleostei: characiformes)

Abstract

In the present paper the first fossil record for the genus Oligosarcus Günther, 1864, is reported, on the basis of specimens collected in Bonaerian stage (Mid-Pleistocene) from the Centinela del Mar locality, Buenos Aires province, Argentina. The present record is based on isolated dentary bones that exhibit a unique combination of traits that allow an unequivocal generic determination. On the basis of detailed comparisons with living species of the genus Oligosarcus, the fossil material is well nested within the species that show a large number of teeth in the second series of the dentary bone. The material here described constitutes the first fossil Characiformes described from the Argentine Pampas.