Viverrid Neuroanatomy: Phylogenetic and Behavioral Implications

External neuroanatomy of 31 genera of living viverrids is surveyed through the use of endocranial casts. Differences in neocortical sulcal patterns suggest two main groupings of subfamilies—mongooses (Herpestinae and Galidiinae) and civets and their relatives (Viverrinae, Paradoxurinae, and Hemigalinae). External neuroanatomy of Cryptoprocta provides no evidence for phylogenetic affinity to any other group of viverrids or to the ancestry of felids. Relative brain size in viverrids averages about 25 percent smaller than in canids; within the range of the family, paradoxurines appear to have relatively large brains and hemigalines relatively small brains. An expanded posterior ectosylvian gyrus in many viverrids suggests an auditory specialization, and the overlapping of the lateral sulcus by the postlateral sulcus in most mongooses suggests a visual specialization. An expanded coronal gyrus in the hemigalines Diplogale and Cynogale suggests increased tactile sensitivity of the face, presumably through elaboration of vibrissae, and a partial central sulcus in the herpestine Atilax suggests increased tactile sensitivity, muscular control of the hands, or both. Viverrids are unique among living carnivorans in including genera that display such primitive features as the lack of a cruciate sulcus (most members of the civet grouping), the lack of an orbital gyrus (most mongooses), and what appears to be an open sylvian sulcus (many genera in both groups). Therefore study of viverrid brains may provide insights into why the neocortex evolved as it did in other groups of carnivorans.