Adaptive radiations occur when an evolutionary lineage diversifies and adapts to use a previously unoccupied niche or underutilized resource, such as Darwin’s Finches. We seek to test hypotheses about the patterns and processes that generate an adaptive radiation by quantifying the morphological diversity of a secretive species-rich group, the New World leaf-litter geckos. We will compare the morphology of island and mainland gecko species using x-rays and photos of preserved specimens.