Osteological correlates of tail prehensility in carnivorans

Abstract

Among mammalian morphological specializations to arboreality, prehensile tails are the least studied. In carnivorans, two phylogenetically and ecologically distant representatives possess truly prehensile tails: the kinkajou Potos flavus, a neotropical procyonid and the binturong Arctictis binturong, a viverrid from south-east Asia. This paper examines osteological characters associated with tail prehensility by comparing carnivorans with and without prehensile tails. The prehensile-tailed taxa are characterized by: (a) a relatively longer proximal caudal region in length and number of vertebrae; (b) more robust distal caudal vertebrae, which possess expanded transverse processes. Comparable features have been also reported for prehensile-tailed primates, indicating evolutionary convergence. These features can be functionally associated with enhanced flexion–extension of the proximal part of the tail and increased strength and flexing capacity at the distal end of the tail. These tail movements are briefly described in free-ranging prehensile-tailed carnivorans.