Semester of Graduation
Master of Arts (MA)
Geography and Anthropology
An enthesis is a marking (tuberosity or impression) on bone where a muscle or tendon attaches and it can be influenced by age, sex, physical activity, and muscle size. This study ascertains whether entheses, long bones, and their respective ratios can be used as an indicator for mode of locomotion in four primate species: Ateles geoffroyi (Geoffroy’s spider monkey), Colobus guereza (mantled guereza), Hylobates lar (lar gibbon), and Macaca mulatta (rhesus monkey). Seven entheses on four long bones were chosen based on importance of the muscle in relation to specific locomotor types, use in other studies, and ease of measurement; for each enthesis and accompanying long bone, a ratio was created which indicated the percentage of length the enthesis occupied on the long bone. Body length and not body mass was used in statistical analysis since a correlation analysis showed these two variables as having a significant, positive association. Comparisons were done among species, sex, and location (captive or wild caught specimen) using a Generalized Linear Model (GLM) with Tukey-Kramer’s tests and Student’s t-tests. The hypothesized pattern for results comparing species will be that C. guereza and M. mulatta group together, H. lar will be separate, and A. geoffroyi will be intermediate between H. lar and C. guereza/M. mulatta due to differences in their locomotion. Results show that five out of seven entheses, one out of four long bones, and one out of seven ratios follow the hypothesized pattern. Reasons for the discrepancy between the hypothesized pattern and results include body length and variable locomotor types within each species. Regarding sex, entheses are sexually dimorphic. Location was not a significant factor among species, which allowed captive and wild caught specimens to be combined into a larger sample. These results show that entheses are indicative of sex and are not affected by captivity. Overall, entheseal length is indicative of locomotor type, but long bone length and the ratio are not.
Otero, Antonio R., "Using Entheseal Length to Infer Locomotor Type" (2019). LSU Master's Theses. 4868.