Head morphological variation in Podarcis muralis and Podarcis sicula: A landmark-based approach

Abstract

The geometry of the cephalic scales in lizards is easily represented by using landmark based approaches. The cephalic scales may prove useful structures in the investigation of the evolution and morphogenesis of lizards because of their biomechanical relationships with the underlying bones and muscular anatomy. In the present paper the head morphology in Podarcis muralis and Podarcis sicula is compared by using geometric morphometrics and Euclidean distance matrix analysis. The head shape in these two species is largely influenced by a shared allometric pattern, with P. sicula displaying a reduced range of variation. This pattern is probably influenced by the cranial morphogenesis at the fronto-parietal suture, and by the parieto-occipital musculature involved in diet and social behaviours. Minor species-specific differences are evidenced, and should be further investigated. © 2007 Brill Academic Publishers.