The interplay between claw morphology and microhabitat use in neotropical iguanian lizards

Traditionally, it has been suggested that variation in locomotor mode should be correlated with variation in the anatomy of the structures responsible for locomotion. Indeed, organisms can expand their ecological niche by using specialized traits of the locomotor system including claws, adhesive pads, etc. Despite the fact that claws are the most common biological mechanism of clinging in vertebrates, little is known about their function or evolutionary relationship to habitat use. The present study focuses on claw morphology across lizards occupying different microhabitats in 57 species of iguanian lizards. Qualitative differences in claw shape were explored by means of digital photographs and quantitative measurements of the length, height and curvature of the claws of both fingers and toes were taken and correlated to information on microhabitat use obtained from the literature. Our analyses showed a strong phylogenetic component, obscuring relationships between morphology and ecology with animals occupying similar habitats often being closely related. Our results also show differences in claw morphology between species that appear to be related to microhabitat use (climbing versus terrestrial species), with the best ecological descriptors being claw length and height. Performance measures and biomechanical analyses of claw function may consequently be better suited to explain the evolution of claw shape in relation to habitat use in this group.Fil: Tulli, María José. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Cruz, Felix Benjamin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Herrel, Anthony. Muséum National d’Histoire Naturelle; FranciaFil: Vanhooydonck, Bieke. University of Antwerp; Países BajosFil: Abdala, Virginia Sara Luz. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; Argentin