Meeting Abstract

5.1  Saturday, Jan. 4 08:00  Morphological integration in the forelimb of musteloid carnivorans FABRE, A.-C.*; GOSWAMI, A.; PEIGNé, S.; CORNETTE, R.; MNHN/UCL; UCL; MNHN; MNHN fabreac@gmail.com

The forelimb forms a functional unit that allows a variety of behaviours and needs to be mobile, yet at the same time stable. Both mobility and stability are controlled at the level of the elbow joint. Here, we study the morphological integration between each long bone of the forelimb at the level of the entire arm, as well as at the elbow joint, in musteloid carnivorans. To do so, we test shape co-variation and the degree of morphological integration using two block partial least square approaches performed on surface 3D geometric morphometric data. Our results show that morphological integration is stronger for bones that form functional units and whose function is crucial in the life-history of these animals. Different results are obtained depending on the level of investigation: for the entire arm, results show a greater degree of shape co-variation between long bones of the lower arm than between the humerus and either bone of the lower arm. Thus, at this level the functional unit of the lower arm is comprised of the entire radius and ulna, permitting rotational movements of the lower arm. At the level of the elbow, results display a stronger shape co-variation between bones allowing stability (humerus and ulna) than between bones allowing mobility (ulna and radius and humerus and radius). Thus, the critical functional unit appears to be the articulation between humerus and ulna providing the stability of the joint.