The family Iguanidae is wide-ranging throughout the New World, stretching from southern Canada to southern Argentina, from the Galápagos through the West Indies. The family includes four other familiar new world lizard genera: the anoles (Anolis), spiny, or fence, lizards (Sceloporous), the island-dwelling curly-tailed iguanas (Leiocephalus), and the South American swifts (Liolaemus). Iguanids may be distantly related to the Old World agamid species, which includes such lizards as the Northern African and Middle Eastern spiny-tailed, or dab, lizards (Uromastyx spp.) and the Philippine and Chinese water dragons (Physignathus spp.).
The Iguaniae subfamily, while being a sometimes
disputed classification, contains the large, strictly herbivorous iguanids.
Other traits of these lizards include their relatively large body size
and diurnal habits. All are ectotherms who behaviorally thermoregulate
their body temperatures, and all lay eggs in deep burrows. They typically
live in dry or rainless or essentially rainless areas, and may be subjected
to seasonal unavailability of foods or seasonal swings in the nutritional
content of their food sources.
