Covariation Between Morphological and Behavioral Evolution in Lizards

Lizards (non-ophidian squamates) are an ecologically diverse, species rich clade of terrestrial vertebrates. Morphologically, lizards are also very diverse; they range over an order of magnitude in body size and numerous groups possess unique skeletal modifications (e.g. casques, horns, cranial kinesis, etc.). Like most vertebrate groups key aspects of skull form are correlated with diet. However, despite their ecological, morphological, and taxonomic diversity, most lizards are thought to employ one of two broad foraging styles or modes (ambush foragers and active foragers). In this study, we perform phylogenetically informed analyses testing for the degree of coevolution between skull morphology and foraging mode. This study differs from previous studies in several important ways. First, we use the most recently published phylogenetic hypotheses for comparison to previous results. Second, we use a combination of geometric morphometrics and traditional linear distance measures to better understand changes in skull shape throughout the history of this diverse clade. Third, we use species-specific behavioral (moves per minute, percent time moving) and morphological data rather than assigning a foraging mode state to an entire family. Therefore, this study is a rigorous attempt to test the adaptive significance of changes in skull form as they pertain to prey capture and processing.