Relative growth of the postcranial skeleton in callitrichines

This study presents the results and suggested functional implications of a metric analysis of skeletal size and shape variation in ontogenetic samples of three callitrichine species:Saguinus oedipus,Saguinus fuscicollis andCallithrix jacchus. Adult interspecific shape differences distinguishS. fuscicollis from the other species. The most notable of these are the intermembral and brachial indices, both of which are significantly higher inS. fuscicollis. Ontogenetic growth patterns are highly conserved across species and the species-specific patterns of growth-related change are virtually identical.Saguinus fuscicollis exhibits a significantly higher intermembral index throughout the period of ontogeny observed in this study, and has a relatively longer radius at any given size or age. The elongation of the forelimb inS. fuscicollis is best seen as an adaptation for increasing the lateral positioning of the forelimbs when foraging on the trunks of large trees.