A large, omnivorous lizard, up to 1.8 m long, that has a fleshy dewlap, a row of spines along the back, and a parietal eye visible as a pale area on the forehead that is sensitive to light. There are two species in the genus Iguana (family Iguanidae), the green or common iguana (I. iguana), found throughout tropical Central and South America and the Caribbean, and often kept as a pet, and the Lesser Antilles iguana (I. delicatissima). The marine iguana (Amblyrhynchus cristatus) of the Galápagos Islands feeds on seaweed and basks on rocks or shelters in rock fissures when not swimming; it is the only extant marine lizard.