Meeting Abstract
P2-150 - Cross-sectional geometry of the hominoid clavicle and its relationship to locomotor behavior Farrell, HN*; Ross, CF; Alemseged, Z; University of Chicago; University of Chicago; University of Chicago hannahfarrell@uchicago.edu
Living hominoids can be readily identified by their orthograde posture and highly mobile shoulder joint, both of which contribute to the extensive locomotor diversity and versatility in this group. Despite its central role as the only bony connection between the upper limb and thorax, the functional morphology of the hominoid clavicle is poorly understood. Studies of external shape disparity suggest that the curvatures present in the anthropoid clavicle reflect differing degrees of arboreal behavior, but there have been no investigations of internal bony architecture. Because cross-sectional geometric properties of long bone diaphyses have often served as analogues for the strength of a bone under bending and torsional loads, calculating such properties along the length of the clavicle may provide insights into how the bone is loaded differently during different locomotor behaviors. Using micro-CT scans of adult hominoid clavicles (Ntotal = 14) and the R package morphomap, we calculated the minimum (Imin) and maximum (Imax) area moments of inertia (second moments of area) as well as the area moments of inertia in the antero-posterior (IAP) and cranio-caudal planes (ICC) at 20 cross-sections distributed evenly across the shaft of the clavicle in order to document variation and investigate its implications for assessing locomotor behavior. Preliminary analysis of these data demonstrates that the distribution of cortical mass across the diaphysis of the clavicle differs between hominoid taxa. Further, it sheds light on the relationship between the internal architecture of the clavicle and locomotor behavior of the taxa under investigation, expanding our current understanding of clavicle morphology and function.