Urocyon, Baird, 1857

Lyras, George A. & Van Der Geer, Alexandra A. E., 2003, External brain anatomy in relation to the phylogeny of Caninae (Carnivora: Canidae), Zoological Journal of the Linnean Society 138 (4), pp. 505-522 : 519

UROCYON

Osgood (1934) considered that Urocyon has an affinity with the South American canids. Later, Clutton-Brock et al. (1976) suggested that Urocyon should be included in the genus Vulpes . Later works ( Wayne et al., 1987a,b; Berta, 1988; Tedford et al., 1995) presented Urocyon as a separate genus, related to Vulpes . In Wayne & O’Brien’s (1987) biochemical analysis of allozymes, Urocyon has a position somewhere at the stem of the Caninae multichotomy.

The region rostral to the presylvian sulcus of Urocyon is much smaller than in the dog-like species and in Nyctereutes (living and fossil), and is comparable to that of Vulpes . This seems to indicate a relatioship with Vulpes . However, the sigmoid gyri form on the dorsal surface of the cerebrum has a heart-shaped outline, which separates Urocyon from all Vulpes spp. and Alopex lagopus , which have a pentagonal outline ( Fig. 9 ), and relates it with Otocyon , Nyctereutes and the South American canids Pseudalopex culpaeus and Cerdocyon thous . Based on these data it is not easy to ascertain the phylogenetic position of Urocyon , apart from its being not a member of the Vulpes -like species.

Figures

Figure 9. Endocasts from living Vulpes spp., Otocyon megalotis, Alopex lagopus and Urocyon cinereoargenteus, dorsal and lateral views.