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
The Lizard Iron Age (Pytheas c. 325 BC) and Roman period, Britain was known as Pretannike (in Greek) and as Albion (and Britons the "Pretani"). The Lizard's coast is particularly hazardous to shipping and the seaways round the peninsula were historically known as the "Graveyard of Ships" ("see below"). The Lizard Lighthouse was built at Lizard Point in 1752 and the RNLI operates The Lizard lifeboat station. There is evidence of early habitation with several burial mounds and stones. Part of the peninsula is known as the Meneage (land of the monks). Helston, the nearest town to the Lizard peninsula, is said