MANDIBLE SHAPE IN MARSUPIAL AND PLACENTAL CARNIVOROUS MAMMALS: MORPHOLOGICAL COMPARATIVE STUDY USING GEOMETRIC MORPHOMETRY

FRANCISCO J. PREVOSTI; GUILLERMO F. TURAZZINI; MARCOS D. ERCOLI; ERIKA HINGST-ZAHER

ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2012 vol. 164 p. 836 - 855

0024-4082

We analysed mandible shape of the orders Dasyuromorpha, Didelphimorphia, and Carnivora using twodimensionalgeometric morphometrics, in order to explore the relationship between shape, size, and phylogeny. Westudied 541 specimens, covering most of the genera of the terrestrial Carnivora (115 species) and a wide sampleof marsupials (36 species). The observed shape variation had an ecological component. As an example, omnivorouscarnivores have thick mandibles and large talonids in the carnassials, while hypercarnivores possess shortmandibles and reduced talonids. There is also a discrimination between different taxonomic groups (i.e. marsupialsand Carnivora), indicating some kind of constraint. Size explains a large percentage of total variance (large specieshad shorter and stronger mandibles, with anteriorly displaced carnassials), was significant when phylogeny wastaken into account with a comparative method, but not when size and shape were optimized on the phylogeny.Carnivora presents a larger disparity and variation in body size, which could be related to the difference in teethreplacement. The optimization of mandible shape on the phylogenetic tree indicates that functional aspects, suchas diet, are a key factor in the evolution of the carnivore mandible, but also that there is a phylogenetic patternthat cannot be explained by differences in diet alone.