PERMANOVA results from Principal component analysis of avian hind limb and foot morphometrics and the relationship between ecology and phylogeny

Principal component analysis has been used to test for similarities in ecology and life habit between modern and fossil birds, however, the two main portions of the hindlimb—the foot and the long bone elements—have not been examined separately. We examine the potential links between morphology, ecology, and phylogeny through a synthesis of phylogenetic paleoecological methods and morphospace analysis. Both hindlimb morphologies and species’ ecologies exhibit extreme phylogenetic clumping, although these patterns are at least partially explainable by a Brownian motion style of evolution. Some morphologies are strongly correlated with particular ecologies, while some ecologies are occupied by a variety of morphologies. Within the morphospace analyses, the length of the hallux (toe I) is the most defining characteristic of the entire hindlimb. The foot and hindlimb are represented on different axes when all measurements are considered in an analysis, suggesting that these structures underg...