Dimorphisme sexuel du crâne de sujets identifiés (collection Olivier, MNHN, Paris): évaluation par morphométrie géométrique

Abstract

The sexual diagnosis based on the skeleton can be performed with visual methods but they appear subjective and require training. Metric methods are also widely used (discriminant functions) but they are known to be specific to the population, which they have been created with. The utmost cause of reproducibility limits inherent to these methods remains the size variable. Recent developments in geometric morphometrics open new research ways. This study evaluates the degree of cranial sexual dimorphism in a 50 identified skeletons sample (25 males and 25 females from the Olivier collection, MNHN, Paris) using geometric morphometrics. These tools allow separating the global size from the cranial shape. The size and shape variables can thus be statistically studied and interpreted. Our sample reveals a strong size-related sexual dimorphism and a more subtle shape-related sexual dimorphism, especially in the faceregion. These differences between males and females are concentrated in the zygomatic bone, the temporal and the nasal aperture. They can be linked to allometry and biomechanics. Perspectives of such results are discussed regarding their potential in the creation of future sex determination methods using the skull with a better reproducibility.