Athletic Capability in Pterosaurs
Pterosaurs had a unique morphology among flying vertebrates and therefore, a direct comparison with living vertebrates regarding their terrestrial locomotion is not possible. In this study, we used the Athletic Capability Indices to infer aspects about the terrestrial proficiency of pterosaurs. We estimated the body mass and the bending strength and axial strength indices for the humerus and femur of 25 specimens of non-pterodactyloid and pterodactyloid pterosaurs. We used linear regression models to investigate the relationship of the Indices of athletic Capability between the two stylopods and the relationship of these indices with body mass. We also compared the values of the indices with those of other extinct and living animals. The results for both indices show higher values for humerus than femur, indicating a higher relative strength of the forelimbs compared to the hindlimbs for bending and axial compression forces, and a negative relationship between both indices with body mass. Compared to those of other quadruped vertebrates, these values are consistent with a good proficiency for terrestrial locomotion for all pterosaurs here analysed, even for basal forms previously thought to have little proficiency in terrestrial locomotion.