Covariation patterns in the postcranial skeleton of moas (Aves, Dinornithidae): A factor analytic study

Abstract

The covariation patterns of the postcranial skeleton in eight species of moas (Aves, Dinornithidae) from the Pleistocene of New Zealand are described using multiple factor analysis. Rotation schemes include an orthogonal Varimax and oblique (direct quartimin) simple structure solutions.Four major patterns of covariation are resolved: a length factor, primarily that of leg length; a width factor, including pelvis width and long bone widths; a sternal breadth factor; and a sternal length-posterior pelvis length factor. The first two patterns represent a functional separation between body size and those aspects of the skeleton, scaling allometrically, adapted to support body weight. The sternal breadth factor may indicate that features contributing to trunk support are independent from those width measurements of the pelvis and hindlimb bones. The sternal length-posterior pelvis length factor reveals a pattern of covariation that is somewhat independent of other patterns (long bone lengths) determining variability in body size.