Humeral Cross‐Sectional Shape in Suspensory Primates and Sloths

In this study, cross‐sections at or near midshaft of the humerus were obtained from anthropoid primates that differ in their use of forelimb suspension, as well as from two genera of suspensory sloths. Imax/Imin ratios were compared within and between groups, and correlations were made with behavioral data. In broad comparisons, observed differences in morphology follow predicted patterns. Humeri of suspensory sloths are circular. Humeri of the more suspensory hominoids tend to be more circular than those of quadrupedal taxa. Humeri of the suspensory atelines are similar to hominoids, while those of Cebus are more like nonsuspensory cercopithecoids. There is, however, considerable overlap between taxa and within finer comparisons variation between species are not in the predicted direction. Thus, although Imax/Imin ratios of the humerus are informative for characterizing generalized locomotor modes (i.e., forelimb suspensory vs. quadrupedal), additional structural information is needed for more fine‐grained assessments of locomotion. Anat Rec, 00:000–000, 2013. © 2013 Wiley Periodicals, Inc.
Source: The Anatomical Record Part B: The New Anatomist - Category: Anatomy Authors: Tags: Full Length Article Source Type: research