Evolution of the cranial ontogeny in marsupials (mammalia)

FLORES, D.A.; SEGURA, V.; GIANNINI, N.; ABDALA, F.

Ciudad Autónoma de Buenos Aires

Congreso; 35th Annual Meeting of the Willi Hennig Society; 2016

the Willi Hennig Society

The quantification of the cranialontogeny in mammals is a topic studied in several works and lineages. In thisreport, we integrate the information of the allometric growth of 15 skullvariables.  We got the confidenceintervals of the multivariate allometric coefficients of those 15 variables for28 species, of which 4 are placentals outgroups (Carnivora and Primates). The24 remaining species conforms the marsupial ingroup including 10 livingFamilies. The confidence intervals were optimized in a well resolved phylogenyof the ingroup, and we detected the phylogenetic signal in the growth of each variable.The optimizations show changes in most internal nodes, although we did notdetect synapomorphies in Marsupials and Placentals basal nodes. Ameridelphia isdefined by an increase of the growth rate of the orbits and height of themuzzle, and decrease of the confidence interval of length of the coronoidprocess. On the other hand, Australidelphia is defined only by a decrease ofthe confidence interval of the height of the coronoid process. We detectedsynapomorphies in almost all internal nodes in both clades, except the nodesthat define Dasyoromorpha and Phalangeridae. The variables with phylogeneticsignals were those related with the mandible growth, and marginally the breadthof the braincase, and the length of the upper toothrow. These dates showimportant fit of the cranial ontogeny in the marsupial evolution.