COMPARATIVE STUDIES ON LIZARDS BASED ON THE CRANIAL OSTEOLOGY OF Lacerta media AND Laudakia caucasia (SQUAMATA: SAURIA)

Abstract

In spite of numerous studies done on the morphometric characters of lizards, information about the detailed characters of their skeletons remains insufficient. In this study, the skulls of two different species of lizards, cleared and double-stained, have been examined and compared: Laudakia caucasia Eichwald, 1831 and Lacerta media Lantz and Cyren, 1920. The aim of this paper is to study the characteristics and peculiarities of the skulls of the two above-mentioned species of lizards in order to facilitate diagnosis and identification of the living species and subfossil remains and to evaluate changes in skull morphology in a phylogenetic context. For doing this, characters of the skull and mandibular elements were studied. The existence of differences between these two genera and families Laudakia caucasia (Agamidae) and Lacerta media (Lacertidae), according to the bone and skull characters, have been explained. The obvious differences that show off are: dimension of the supratemporal fossae, thickness of the individual bones, and head length/width ratio. Other obvious differences are the type of dentition, differences in form, size and special manner of joining bones like existence of differences in lower jaw and braincase architecture, and reviewing some differences in the skulls of two different phylogenetic lines.