Text and pictures from : "Field giude to snakes and other reptiles of southern Africa" - by Bill Branch
CRAG LIZARDS
These beatyful tyrants are some of the largest cordylids, surpassed in size only by the sungazer, Cordylus giganteus. They are very similar in the appearance to the girdled lizards, Cordylus, differing only in that the neck and back are usually covered with granular scales, the body lack osterderms, and the tail is less heavily spined. Rock living, crag lizards usually inhabit large fissure in a shattered boulder that commands a good vantage point from which to spot potential danger and forage for food. Unlike the flat lizards, Platysaurus, they are not sociable, and a crack is usually occupied by a single idividual. They may however, aggregate in diffuse colonies in good habitat and hibernate communaly in deep cracks. They eat a wide range of large invertebrates, including beetles, crickets and grasshoppers, and also take small vertebrates, prticularly other lizards. They have tremendously strong jaws and unusual, hinged skull structure that allows the shape of the head to thicken if the jaws are clammed shut. This is effectively used as a defence; the lizard wedges its head into a narrow part of a crack, and as long as it clenches its jaws, the top of the head and lower jaw will be tightly jammed against the rock walls. To prevent damage to the lizard, the scales o nthe top of the head are thickened with bony osterderms. Their bulldog-like tenacity makes it almost impossible to pull them from their retreats. Although large and agressive, they are very wary, and quickly retreat into their crack at the first sign of danger. Viviparous, the female give birth to 7 young in late summer. These disperse and are usually found in marginal habitats on the lower mountain slopes. Later as they grow and mature they seek more permanent homes in more prominent positions. There are seven species, and all are endemic. The blue-spotted girdled lizard, C.coeruleopunctatus is closely related to the graceful crag lizard, P.capensis, and dwarf crag lizard, P.nebulosus, and should perhaps be transferred to this genus. This illustrates the close realtionship between the two genra. Crag lizards are disrtibuted in a wide arc in the old mountain escarpment of South Africa, from the Cedarberg in the west through the Cape fold mountains and the inland mountains of E.Cape, KwaZulu-Nathal and Mpumalanga, to the Soutpansberg in N.Province.