New fossil remains of Quaternary capybaras (Rodentia: Caviomorpha: Caviidae) from the intertropical region of Brazil: morphology and taxonomy

Abstract

In this work, new fossils of Hydrochoerinae rodents (Caviomorpha: Caviidae: Hydrochoerinae) from the Quaternary of the intertropical region of Brazil are described, almost 180 years after the first fossils of these animals were found in Lagoa Santa, Minas Gerais. The fossils studied herein were collected in caves of States of Bahia (Toca dos Ossos and Lapa dos Brejões) and Minas Gerais (Lapa Vermelha cave, Lagoa Santa karst). The analyzed material is assigned to the extinct large rodent Neochoerus sulcidens and is composed of skull portion, upper and lower cheek teeth, mandible, humerus, innominate, femur, tibia, and calcaneus. The specimens were assigned to this taxon based on the presence of an M3 with 14 prisms; incisor alveolus reaching the pr. II do m2; anteriormost level of the palatine at the level of the Pr. II of the M2; and larger size than the living species. The p4 is mesiodistally longer than the m1 and m2, distinct from previous interpretations in which the mesiodistal length of the p4 of N. sulcidens would be smaller than the m2, indicating the presence of a variable character. Except for the differences in size, the postcranial bones of N. sulcidens are quite similar to H. hydrochaeris.