Iguanas

Iguanas are large, ancient, herbivorous lizards with a stocky trunk, long, slender tail, scaly skin, and a single row of spines from the nape of the neck to the tip of the tail. On either side of the head is an eye with a round pupil and with moveable lids. The well-defined snout has two nostrils, the mouth houses a short, thick tongue, and dangling beneath the chin is a "dewlap," or throat fan. Iguanas are well equipped for speed and climbing with four short, thick, powerful legs, each with five long thin toes tipped with strong claws. Iguanas are found in warm, temperate, and tropical zones and, depending on the species, live in trees, holes, burrows, and among rocks. Iguanas are oviparous (egg-laying), diurnal (active during the day), and ectothermic (cold-blooded), thermoregulating by basking in the sun or sheltering in the shade. Iguanas are found only in the New World, and were completely unknown in the Old World until European explorers discovered the Americas.