[Cranial and mandibular morphology of the Indrinae. Contribution of Procrustes methods and Fourier analysis].

Although it is universally accepted that the Indridae family is monophyletic, there is no such unanimity about how the extant species of the Indrinae sub-family are related. Cranium and mandible disparity among Indri indri, Propithecus diadema, Propithecus verreauxi and Avahi laniger is analysed by geometrical morphometric methods and interpreted in adaptive terms. We compare results obtained by two techniques: Procrustes superimpositions for skulls and elliptical Fourier analysis for jawbones. In both studies, the three genera are clearly isolated. Avahi laniger is the species with the most paedomorphic cranium while Indri indri has the most 'juvenile' mandible. Cranial morphology is governed principally by orbit volume and body size, while jaw shape is related to diet (enlargement of the gonial region).