Paleoneurología de Dolicavia minuscula (Rodentia, Caviidae) y Paedotherium insigne (Notoungulata, Hegetotheriidae) del Plioceno de Buenos Aires, Argentina.

DOZO, MARÍA TERESA

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 1997 vol. 34 p. 427 - 435

0002-7014

Based on a paleoneurological study, the external neuromorphological characters of a Caviidae rodent (Dolicavia minuscula) and a Hegetotheriidae notoungulate (Paedotherium insigne) from Chapadmalal Formation, are interpreted. The endocasts of these species show similar external brain morphologies including the same pattern of neocortical sulci. Comparisons with brains of their possible ecological equivalents, rodents and lagomorphs, suggest that the brain of Paedotherium insigne is similar to those of Caviidae, particularly Caviinae (Cavia, Dolicavia). Also, this brain shares the same pattern that it is interpreted in others Hegetotheriidae (Hegetotherium, Pachyrukhos). It is proposed that the neuromorphological convergence between Hegetotheriidae and Caviidae has been closer than it is inferred from the osteological and dental characters. Indices of encephalization were computed. The relative brain size of P. insigne is lower than that of D. minuscula, being the last one at the level of the living Caviidae.