Meeting Abstract
Pygopodids are an enigmatic group of limb-reduced geckos that live in a variety of habitats within Australia and New Guinea. Despite low taxonomic diversity, pygopodids exhibit a wide array of skull morphologies, sometimes within a single genus. For example, Aprasia from Western Australia differ from Eastern and Central species by elongating the parabasisphenoid rostrum and reducing the epipterygoid. To investigate differences in skull shape across pygopodids and assess potential ecological associations, CT scans of 12 specimens from six genera were used for 3D geometric morphometrics. We recorded 29 landmarks in Landmark Editor, and used Geomorph to perform Generalized Procrustes Alignment, Principal Components Analysis, and MANOVA to test for associations with habitat (fossorial, ground, low-shrub, high-shrub). Habitat correlated significantly with shape differences. PC1 (skull depth, orbit shape) explained 46% of the variation whereas PC2 (snout elongation, occipital shape) explained 15%. Fossorial taxa (all Aprasia we included) were widely separated from other habitat types along PC1, and the highly elongate Lialis was isolated in shape space. Within Aprasia, taxa separated along PC2 into Western and Central/Eastern clusters, and MANOVA of Aprasia species confirmed geography to be a significant factor. We suggest that the two Aprasia morphotypes, and a second genus Ophidiocephalus, took different evolutionary paths to achieve head shapes conducive to fossoriality. However, less is known about the locomotor and feeding patterns of pygopodid species, which also may influence morphology and could drive the separation within habitat types.
