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
Greater short-horned lizard in the mountains. This species is frequently found in a wide range of habitats like shortgrass prairies, sagebrush deserts, and juniper, pine, or fir forests. The soil in these habitats can be stony or rocky but usually has fine loose soil or sand present. The greater short-horned lizard is more cold tolerant than other species and is able to reach higher elevations and a greater distribution where the temperature is much cooler. Greater short-horned lizard The greater short-horned lizard ("Phrynosoma hernandesi"), also commonly known as the mountain short-horned lizard, is a species of lizard endemic to western North America. Like