Supraorbital ossifications in geckos (Reptilia: Gekkonidae)

Abstract

Two types of supraorbital ossifications occur in members of the family Gekkonidae. True osteoderms, embedded within the dermis, overlie the orbital region in Tarentola and Geckonia. In Teratoscincus and Aristelliger, small bones in a supraorbital position, for which the term parafrontal bones or ossa parafrontalia is suggested, are found within the brillar fringe. These elements lie beneath the dermis in the plane of the frontal bone, and differ from osteoderms in their irregular shape and lack of correspondence with overlying epidermal scales. Parafrontal bones have been derived independently in the lineages in which they occur and their homologies to supraorbital ossifications in other lizards, if any, remain unclear.