Yet the interspecific diversity and intraspecific variability of long bone structural properties remain poorly understood, particularly in a fossil record that is often fragmentary. In the lower limb, this diversity appears to reflect both functional adaptations to the biomechanics of bipedal walking and running, influenced by mobility level and terrain variation, and intrinsic factors such as overall robusticity or body proportions. Recent studies show that certain structural properties of long bones also carry a phylogenetic signal. This raises the question of the balance between functional adaptation and phylogenetic constraints in shaping bone structure.