Locomoting into New Niches: Limbs, Ecology, and Evolution in Mustelid Mammals
· Managed by: Brandon Kilbourne
A pivotal aspect of locomotion in limbed vertebrates is that the limb bones must be able to withstand the forces incurred during locomotion while transmitting the forces generated by limb muscles. The morphology of a limb bone is intimately tied to its mechanical loading regime, and, as such, long bone morphology should reflect ecological specializations. Using museum specimens, this project measures traits associated with bone internal structure, including bone cross-sectional area (CSA), second moment of area (SMA), and section modulus (MOD). CSA and SMA provide the bone’s resistance to axial and bending loads, respectively. Though bone cross-sectional properties have been studied in terms of interspecific scaling relationships or during the ontogeny of individual species, it has yet to be investigated how bone cross-sectional properties vary within a functionally diverse lineage. Moreover, it also remains unknown if bone cross-sectional traits are subject to distinct selective pressures as lineages evolve new locomotor habits. Given the locomotor diversity of mustelid mammals, including climbing, digging, and swimming specialists, this project investigates whether bone cross-sectional properties differ among locomotor habit further fitting cross-sectional properties to models of trait diversification.