The Iguanidae are a family of lizards composed of iguanas and related species. Several classification schemes have been used to define the structure of this family. The 'historical' classification recognized all New World iguanians, plus Brachylophus and the Madagascar oplurines, as informal groups and not as formal subfamilies. Frost and Etheridge (1989) formally recognized these informal groupings as families. Macey et al. (1997), in their analysis of molecular data for iguanian lizards recovered a monophyletic Iguanidae and formally recognized the eight families proposed by Frost and Etheridge (1989) as subfamilies of Iguanidae. Schulte et al. (2003) reanalyzed the morphological data of Frost and Etheridge in combination with molecular data for all major groups of Iguanidae and recovered a monophyletic Iguanidae, but the subfamilies Polychrotinae and Tropidurinae were not monophyletic. Townsend et al. (2011), Wiens et al. (2012) and Pyron et al. (2013), in the most comprehensive phylogenies published to date, recognized most groups at family level, resulting in a narrower definition of Iguanidae. Family Iguanidae Family CorytophanidaeFamily CrotaphytidaeFamily HoplocercidaeFamily Iguanidae