Meeting Abstract
Anurans (frogs) are the most speciose lissamphibian clade, and they exhibit astonishing cranial diversity, creating a significant challenge for quantifying cranial morphology across the clade. Here we quantify anuran cranial morphology using high-density landmarks and semilandmarks for 173 anuran species sampling every extant anuran family. The complex morphology of the frog skull is represented by a total of 995 landmarks and semilandmarks across 15 cranial regions, making this the most comprehensive dataset of anuran cranial morphology to date, in terms of both taxonomic sampling and density of shape data. With these shape data we investigate ecological, developmental, phylogenetic and allometric influences on the morphology, evolutionary rate and disparity of each cranial region. Microhabitat use is a strong influence on morphology, evolutionary rate and disparity. Semi-fossorial, fossorial, and aquatic species are the most disparate and fastest-evolving, and this pattern is most evident for jaw suspensorium cranial regions. Fossorial and aquatic species occupy distinct regions of cranial morphospace, with fossorial species associated with dorsoventrally taller skulls. Developmental strategy, in contrast, exhibits either a non-significant, or a very weak, influence on morphology, evolutionary rate and disparity. However, ossification sequence timing significantly influences evolutionary rate and disparity across frogs, with later-ossifying bones significantly more disparate and faster-evolving than early-ossifying bones. Phylogeny and allometry are both significant influences on frog crania, and cranial modules are differentially influenced by phylogenetic, allometric, and ecological effects.
