Iguania is an infraorder of squamate reptiles that includes iguanas, chameleons, agamids, and New World lizards like anoles and phrynosomatids.

Using morphological features as a guide to evolutionary relationships, the Iguania are believed to form the sister group to the remainder of the Squamata,[1] which comprise nearly 11,000 named species, roughly 2000 of which are iguanians.

[2] The order has been under debate and revisions after being classified by Charles Lewis Camp in 1923 due to difficulties finding adequate synapomorphic morphological characteristics.

[citation needed] Today they are scattered occurring in Madagascar, the Fiji and Friendly Islands and Western Hemisphere.

[4] The Iguania currently include these extant families:[5][6] Below is a cladogram from the phylogenetic analysis of Daza et al. (2012) (a morphological analysis), showing the interrelationships of extinct and living iguanians:[3] †Hoyalacerta sanzi †Huehuecuetzpalli mixtecus †Pristiguana brasiliensis †Mimeosaurus crassus †Priscagama gobiensis †Phrynosomimus asper Physignathus Agama Uromastyx Leiolepis Rhampholeon Brookesia †Polrussia mongoliensis †Igua minuta †Isodontosaurus gracilis †Anchaurosaurus gilmorei †Zapsosaurus sceliphros †Saichangurvel davidsoni †Temujinia ellisoni †Ctenomastax parva Enyalioides Morunasaurus Hoplocercus Polychrus gutturosus Polychrus marmoratus Polychrus femoralis †Afairiguana avius Leiosaurus Anisolepis Enyalius Pristidactylus †Anolis electrum Anolis occultus Anolis heterodermus Anolis vermiculatus Laemanctus Basiliscus Corytophanes Iguanidae Crotaphytus Gambelia Phrynosoma Uta Petrosaurus Sceloporus Urosaurus Chalarodon madagascariensis Oplurus quadrimaculatus B Oplurus quadrimaculatus A Oplurus cyclurus †Uquiasaurus Phymaturus Ctenoblepharys Liolaemus Leiocephalus Stenocercus Tropidurus Uranoscodon The extinct Arretosauridae (Paleogene iguanians from Central Asia) are alternatively classified in either the Acrodonta with other Old World iguanians, or in Pleurodonta as a sister group to the Crotaphytidae.