Sexual dimorphism and body shape differences in hip bone morphology between Homo sapiens and Neanderthal lineage individuals.

Abstract

The pelvis as a whole and the hip bones are the best skeletal elements for determining sex in humans, as their pattern of sexual dimorphism is based on women's ability to give birth to a full-term fetus. Additionally, an individual's body type also has a significant effect on pelvic shape, which could, in turn, influence the pattern of sexual dimorphism. It has been demonstrated that 3D geometric morphometrics (3DGM) can distinguish between male and female hip bone morphology in anatomically modern humans. Therefore, this study employs 3DGM methodology to analyse and compare hip bone morphology of individuals from the Neanderthal lineage, as well as a specimen of early Homo, in a comparative framework of 46 H. sapiens of known sex. The Neanderthal lineage individuals were distributed along modern male and female morphologies, coinciding with their traditional sexual assessment, based on differences in pubic length, iliac width, and greater sciatic notch aperture. These results point to a similar coxal sexual dimorphism pattern in both lineages. Body shape does not seem to influence the dimorphic pattern, but the results show a gradient from archaic coxal morphology present in early Homo to the derived Neanderthal morphology, where the pre- Neanderthal individual has a more Neanderthal-like morphology than the H. heidelbergensis individual.