Cranial and mandibular morphology of the Indrinae investigated by Procrustes methods and Fourier analysis.

Although it is universally accepted that the Indridae family is monophyleti c, there is no such unanimity about how the extant species of the Indrinae sub-family are related. Cranium and mandible disparity among Indri indri, P ropithecus diadema, Propithecus verreauxi and Avahi laniger is analysed by geometrical morphometric methods and interpreted in adaptive terms. We comp are results obtained by two techniques: Procrustes superimpositions for sku lls and elliptical Fourier analysis for jawbones. In both studies, the thre e genera are clearly isolated. Avahi laniger is the species with the most p aedomorphic cranium while Indri indri has the most 'juvenile' mandible. Cra nial morphology is governed principally by orbit volume and body size, whil e jaw shape is related to diet (enlargement of the genial region). (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.