Endocasts of amphicyonid carnivorans. American Museum novitates ; no. 2694

Abstract

"Endocranial casts of 10 genera of amphicyonids, ranging in age from about 35 my to 10 my, reveal evolutionary trends of increase in relative brain size and expansion and increased folding of the neocortex. Amphicyonids had a distinctive pattern of cerebral convolutions, characterized by the presence of a long ectolateral sulcus, a short sulcus between the caudal ends of the ectolateral and suprasylvian sulci, and a complete, unopercularized ectosylvian sulcus. The ectolateral sulcus is a derived character amphicyonids share with canids, in contrast to a derived feature of basicranial circulation that links amphicyonids to ursids"--P. [1].