CONICET | Buscador de Institutos y Recursos Humanos

Carnivora is a group of mammals specialized on preying on other vertebrates. However, there is a huge variation of feeding habits, from strictly hypercarnivores to exclusively herbivores. The morphology of the skull partly conditions the dietary habits, whereas evolutionary history and constraints affect shape variation in this group. We study the influence of dietary habits, phylogenetic relationships and allometry on the shape of the cranium of carnivorans. We used 2D geometric morphometry of the cranium and performed Principal Component Analysis (PCA) to study the distribution of the specimens in the morphospace in relationship to diet habits and taxonomy. Also, a redundancy analysis (RDA) was used to study the influence of dietary habits, phylogenetic relationships and allometry in shape. We found that carnivorans mainly grouped by taxonomy in the PCA, with Arctoidea, Canidae and Feliformia being separated. The last clade showed a separation in three distinct groups, Felidae, Hyanenidae plus Nimravidae, and the rest of Feliformia. The last group included a large variation of ecomorphs, grouping species of Herpestidae, Eupleridae and Viverridae between Canidae and Arctoidea. All these groups showed some overlap between them. The RDA showed strong influence of the phylogeny (about 80%), diet (about 37%) and a softer influence of size (about 5%). When diet and phylogeny were analyzed together, the shape variance explained exclusively by diet was very small, and most of the variance explained by diet was also explained by phylogeny. Results indicate that cranial shape is mainly explained by phylogenetic relationships, what could point to the existence of some kind of constrain. Dietary habits are also structured phylogenetically, which indicates that diet was also a relevant factor in the evolution of the group.