SHAPE EVOLUTION IN MAMMALIAN CARNIVORES (ORDER CARNIVORA): A “PHYLO-MORPHOMETRIC” APPROACH.

PREVOSTI, F.J.; ERCORLI, M.; GUILLERMO F. TURAZZINI

Congreso; 9th International Congress of Vertebrate Morphology; 2010

ICVM

The morphology of the mandible and the lower dentition carry information regarding the diet ofdifferent species of carnivores. Consequently, several studies were published analyzing therelationship between the shape of the mandible and the dietary habits, based on differentmethods such as morphometric indexes and traditional morphometrics (i.e. multivariatestatistics using measurements). Other works explored the presence of constraints or modularityin the mandibles, but the evolution of mandible shape in a phylogenetic framework remainsunknown. We use new algorithms that allow the optimization of geometric morphometricconfigurations on phylogenetic trees to explore the evolution of mandibular shape in livingcarnivores. The optimization of the shape of the mandible on the phylogeny shows that mostinternal nodes have generalized shapes and most of the extreme changes take place at terminalbranches, which correspond to “derived” species or genera (e.g. Potos flavus). Some interestingchanges of the shape happen at Family nodes, for example Ursidae has a short and strong ramus,an anteriorly placed carnassial and a large canine, while Canidae has longer and slenderhorizontal ramus when compared to internal nodes of the phylogeny. The relationship betweenshape and changes in size in the whole tree remains unclear, but some of those changes canhappen in the same node (e.g. Ursidae presents an increment in size and while changes to adifferent mandible pattern). This optimization must be tested in the future including a bettersample of fossils