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
Sagebrush lizard cats also prey on them. There are three valid subspecies of the sagebrush lizard, which differ in their geographic distributions, markings, and number of scales. The subspecific name, "vandenburgianus", is in honor of American herpetologist John Van Denburgh. Sagebrush lizard The sagebrush lizard ("Sceloporus graciosus") is a common species of phrynosomatid lizard found at mid to high altitudes in the western United States of America. It belongs to the genus "Sceloporus" (spiny lizards) in the Phrynosomatidae family of reptiles. Named after the sagebrush plants near which it is commonly found, the sagebrush lizard has keeled and spiny scales running along