External brain anatomy in relation to the phylogeny of Caninae (Carnivora:Canidae)

Caninae is one of the most studied mammalian groups, nevertheless there are relatively few comparative studies on their neuroanatomy. This work contributes to a better knowledge of this subfamily, since it describes the external cerebrum anatomy of 29 out of the 35 living Caninae species, 11 of which are described for the first time. Information about their frontal region appears to be a welcome supplement to the study of the phylogeny. Two distinctive features are recognized, that can be traced back in the fossil record: the sulcal pattern medial to the coronal sulci, and the shape and relative size of the proreal gyrus. Four types are described for the first feature: (1) orthogonal: Canis, Lycaon, Cuon, Atelocynus, Speothos, (2) pentagonal: Vulpes, Alopex, Otocyon, daggerEucyon, (3) parenthesis-like: daggerDusicyon, Pseudalopex, Chrysocyon, (4) heart-shaped: Urocyon, Cerdocyon, Pseudalopex culpaeus, Nyctereutes. Three types are described for the second feature: (1) elongated and bilaterally compressed: Canis, Cuon, Lycaon, Atelocynus, Speothos, Cerdocyon, daggerDusicyon, Chrysocyon, Pseudalopex, daggerNyctereutes sinensis, daggerN tingi, (2) small: Vulpes, Otocyon, Urocyon, Alopex, (3) wide and low: Nyctereutes procyonoides. On the basis of these features some phylogenetic interpretations are presented: the fossil Asian Nyctereutes is close to Cerdocyon, Speothos is close to Atelocynus, Chrysocyon is not related to Canis, Urocyon differs from Vulpes and Pseudalopex culpaeus differs from the rest of the Pseudalopex species. (C) 2003 The Linnean Society of London. Zoological Journal of the Linnean Society.