Deciphering locomotion in reptiles: application of elliptic Fourier transforms to femoral microanatomy

Abstract Reptiles represent one of the most diverse groups tetrapod vertebrates. Extant representatives reptiles include lepidosaurs (lizards), testudines (turtles) and archosaurs (crocodiles birds). In particular, they show an important locomotor diversity with bipedal, quadrupedal facultatively bipedal taxa. This is accompanied by substantial microanatomical disparity in limb bones. Although many studies have highlighted link between locomotion bone microstructure, latter has never been quantitatively studied from angular perspective. Indeed, some taxa heterogeneity cross-section. Here we show, using elliptic Fourier transforms statistical analyses integrating phylogeny, how parameters measured on reptilian femoral cross-sections, such as compactness, can be related to this clade. phylogeny appears a significant impact our results, that functional signal exists. bipeds quadrupeds present craniolateral-caudomedial dorsoventral deficit respectively. reflects cross-sectional eccentricity these directions relate forces acting upon femur different postural contexts. work contributes deciphering complex interplay microanatomy reptiles.