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
Madagascar girdled lizard Madagascar girdled lizard The Madagascar girdled lizard or Madagascar plated lizard ("Zonosaurus madagascariensis") is a species of lizard in the family Gerrhosauridae. It is found in Madagascar, some outlying islands (Nosy Be and the nearby islands; Grande Glorieuse) and the Seychelles (Cosmoledo). This generally common lizard is found in a range of habitat types, including open and degraded humid forest at mid and low altitudes. It also occurs in plantations. On Cosmoledo, it occurs in open shrubland. This oviparous lizard grows to total length. http://ars.els-cdn.com/content/image/1-s2.0-S1055790313002534-fx1.jpg The family Gerrhosauridae shares the strongest evolutionary linkages to Asian and South American Species. However,