Comparative structural analysis of the Neanderthal femoral shafts BD 5 (MIS 5e) and CDV-Tour 1 (MIS 3) from La Chaise-de- Vouthon, Charente, France

Neanderthal femoral shaft of BD 5 (MIS 5e), representing a young adult female, and CDV-Tour 1 (MIS 3), an adult male, are both from the site of La Chaise-de-Vouthon, Charente, but are separated by about 80,000 years. In order to identify possible evolutionary morpho-structural changes during this time span, we present a comparative analysis of their internal and external structure. In addition to the morphological characteristics and changes in their external diameters at midshaft and subtrochanteric levels, we quantified, from their microtomographic record (μCT), the cross-sectional geometric properties of these specimens at 50 %, 65 % and 80 % of the biomechanical femoral length and analyzed the morphometric maps of the topographical distribution of cortical bone. Despite differences likely related to sexual dimorphism, both shaft of La Chaise share among themselves but also with all European Neanderthals femurs considered in this study, the typical structural features of this taxon. Indeed, at least compared to the quantitative parameters measured and specimens available for this type of analysis, during the time period MIS 5-3 we did not notice any obvious changes in the endostructural arrangement and in the biomechanical properties of the Neanderthal femoral shaft.