Meeting Abstract
Habitat structure has a profound influence on the form, function, and behavior of animals. Although one of the best examples of ecomorphological specialization can be found in Anolis lizards, few relationships between limb length and habitat have been found in other lizard taxa. Further, few studies demonstrate a functional consequence of this ecomorphological relationship. Lygosomine skinks are extremely diverse, both ecologically and morphologically; they occupy habitats ranging from leaf-litter to cliffs and tree trunks, and they range from stocky with highly robust limbs to elongate with reduced or absent limbs, each form arising multiple times. Such patterns suggest a tight ecomorphological relationship, but few genera in this group have been studied and it is unclear if the relationship will hold across a broader sampling of species. We obtained morphological and ecological data for 103 species of lygosomine skinks to test for the relationship between limb morphology and habitat use in an evolutionary context. We compared non-phylogenetic and phylogenetic models, with and without Ornstein-Uhlenbeck (OU)-transformed branch lengths, and consistently found the OU models to best fit the data. We show that saxicolous and arboreal species have longer and more equal limbs than terrestrial species, and that these longer limbs translate to longer limb spans that would be advantageous for climbing on curved, vertical surfaces. Interestingly, however, although longer limbs should increase the distance between the center of mass and the edge of the base of support (static stability), this calculated variable did not correlate with habitat use. These data suggest that the different behavioral, but not stability, requirements of arboreality and fossoriality can explain the morphological patterns observed.
