Lizard heads called the parietal eye, a basal ("primitive") feature also present in the tuatara. This "eye" has only a rudimentary retina and lens and cannot form images, but is sensitive to changes in light and dark and can detect movement. This helps them detect predators stalking it from above. Until 2006 it was thought that among lizards, only the Gila monster and the Mexican beaded lizard were venomous. However, several species of monitor lizards, including the Komodo dragon, produce powerful venom in their oral glands. Lace monitor venom, for instance, causes swift loss of consciousness and extensive bleeding through its
Peloponnese wall lizard Peloponnese wall lizard The Peloponnese wall lizard ("Podarcis peloponnesiacus") is a species of lizard in the family Lacertidae. It is endemic to the Peloponnese region of southern Greece. Its natural habitats are Mediterranean-type shrubby vegetation, rocky areas, arable land, pastureland, plantations, and rural gardens. The Peloponnese wall lizard grows to a snout-to-vent length of about with a tail about twice the length of the body. Males are in general rather larger than females. It is a robust species with adult males having particularly large heads. The colouring is rather variable, basically being some shade of olive- or greyish-brown with a