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
Abbott's crested lizard Abbott's crested lizard Abbott's crested lizard ("Gonocephalus abbotti") is a species of lizard in the Agamidae family. It is endemic to Thailand. Both the specific name, "abbotti", and the common name are in honor of American naturalist William Louis Abbott. It is also known as Abbot's anglehead lizard. Abbott's crested lizard is about in total length (including tail). The most distinctive anatomical features are the triangular bony crest on the face and the upturned nose. The colors of the dragon range from tan to green with light and dark dots on the body. The most common color is an olive