Meeting Abstract
Reconstructing locomotor adaptations of fossil taxa is facilitated with a comprehensive understanding of the locomotor biology of their closely related extant relatives, which can elucidate broad patterns of locomotor evolution of a clade. For fossil primates, tarsal morphology should be especially useful since feet interact directly with the substrate on which an animal moves, and tarsals are relatively abundant in the primate fossil record. Specifically, the morphology of intertarsal joints is hypothesized to reflect specializations for movements that facilitate locomotion on arboreal and/or terrestrial substrates, with subtalar and transverse tarsal joints primarily responsible for inversion and eversion, and overall midfoot range of motion responsible for different foot postures. Hypotheses concerning the relationship between the shapes of, and movements at these joints, however, remain untested, especially in nonhuman taxa. This study presents 3D data on articular surface orientation and shape on virtual surface models of the calcaneus, talus, cuboid, and navicular in a diverse sample of anthropoids to identify osteological correlates of posture and motion at the talocrural, subtalar, and transverse tarsal joints. This study also presents an approach that will test these functional correlations using in vivo XROMM data of macaque locomotion on different substrates. The eventual goal is to combine the 3D morphometric results with the XROMM data to facilitate interpretations of primate locomotor evolution.
