Comparaison tridimensionnelle des crânes de Pan et Pongo par superpositions procrustéennesComparison of skulls of Pan and Pongo using tridimensional procruste superimpositions.

Comparative anatomy of the skulls of Pan and Pongo using procruste superimposition shows that airorynchy, classically described as a change in palatal tilting, is a complex movement involving a downward shift of the posterior part and an upward shift of the anterior part. Our 3D analysis shows that airorynchy could be interpreted as the functional consequence of the anatomic differences between the temporal muscle mass of those two genera. It also appears that the palatal tilting and the morphology of the supra-orbital torus are two independent features. A statistical test shows that the torus development is dependant, at least partly, on the relationship between the orbital cavity and the frontal bone.