Xenosaurus seems to be an offshoot intermediate between the Iguanidae and the Anguidae; a degraded form of latter is perhaps Aniella of California, whilst Heloderma and Lanthanotus are also specialized and isolated offshoots.
Zonuridae and Anguidae assume a central position, with Agamidae and Iguanidae as two parallel families (not very different from each other) of highest development, one in the Old World, the other in America.
Rock-lizard, the vernacular name of Sceloporus torquatus which is one of the Iguanidae misspelt and misapplied.
In their general structure the Iguanidae closely resemble the Agamidae, from which they differ mainly by the pleurodont dentition.
IGUANA, systematically Iguanidae (Spanish quivalent of Carib iwana), a family of pleurodont lizards, comprising about 50 genera and 300 species.