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
Mexican mole lizard Mexican mole lizard The Mexican mole lizard (Bipes biporus), commonly known as the five-toed worm lizard, or simply as "Bipes", is a species of amphisbaenian, which is endemic to the Baja California Peninsula. It is one of four species of amphisbaenians that have legs. It should not be confused with the axolotl, a salamander ("Ambystoma mexicanum"), which is usually called "ajolote" in Spanish. It is commonly found in Baja California. They are pink, worm-like lizards, snout-to-vent length and in width, that live for one to two years. Their skin is closely segmented to give a corrugated appearance, and like earthworms,