Iguanidae

Iguanidae (iguanas, basilisks, anoles; order Squamata, suborder Sauria) A family of lizards, with terrestrial, arboreal, burrowing, and semi-marine forms, which are the New World counterparts of the Old World Agamidae, but distinguishable by their pleurodont teeth. Typically, iguanids are long-limbed and agile. Dorsal crests, throat appendages, and ‘helmets’ are common. Iguana iguana (common iguana or green iguana) of S. American tropical forests is large (up to 1.8 m long), principally herbivorous, and has a short, fleshy tongue, serrated teeth, a throat dewlap, and a spiny crest along the back; it dives into water if startled. Phyrnosoma species (horned lizards) are flat and squat with short tails, their bodies covered with spiny tubercles, and they can burrow backwards into the sand; if disturbed they may squirt blood from the corners of their eyes. Amblyrhynchus cristatus (marine iguana) of the Galápagos Islands is the only extant marine lizard; it feeds on seaweeds and basks on rocks or shelters in fissures when not swimming. The 165 Anolis species (anoles) are small, slender, with long, whip-like tails, and have adhesive pads on their clawed toes; in some these pads have enlargements allowing the lizard to ‘parachute’ (i.e. to slow their rate of descent when falling, which allows them to jump to the ground from considerable heights). Anoles are adept at colour change. The arboreal Basiliscus (basilisks) of Mexico and Ecuador are excellent swimmers but also fast, bipedal runners on land, and over the surface of water! Adults develop a casque on the head, which is larger in males. They feed on fruit and small animals. There are more than 700 species in the family, found mainly in the New World, but also in Madagascar and some Pacific islands.