Iguania
Encyclopedia
Iguania is the suborder of Squamata
(snakes and lizards) that contains the iguanas, chameleon
s, agamids, and "New World
lizards" such as anoles and Phrynosomatidae
. The Iguania were previously believed to form the sister group to the remainder of the Squamata based on morphological
characteristics, however molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha
and closely related to snakes. They are largely arboreal and have primitively fleshy, non-prehensile tongues, but this condition is obviously highly modified in the chameleons. Traditionally, the clade
includes the following families::
Extinct:
More recently, a revised delimitation of families is proposed to be more phylogenetically accurate. Most notably, this reduces the Iguanidae to a core set of taxa, upranking many of its former subfamilies to full iguanian families. See Iguanidae
article for further information.
Squamata
Squamata, or the scaled reptiles, is the largest recent order of reptiles, including lizards and snakes. Members of the order are distinguished by their skins, which bear horny scales or shields. They also possess movable quadrate bones, making it possible to move the upper jaw relative to the...
(snakes and lizards) that contains the iguanas, chameleon
Chameleon
Chameleons are a distinctive and highly specialized clade of lizards. They are distinguished by their parrot-like zygodactylous feet, their separately mobile and stereoscopic eyes, their very long, highly modified, and rapidly extrudable tongues, their swaying gait, the possession by many of a...
s, agamids, and "New World
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
lizards" such as anoles and Phrynosomatidae
Phrynosomatidae
Phrynosomatidae is a diverse family of lizards, found from Panama to the extreme south of Canada. Many members of the group are adapted to life in hot, sandy deserts, although the spiny lizards prefer rocky deserts or even relatively moist forest edges, and the short-horned lizard lives in prairie...
. The Iguania were previously believed to form the sister group to the remainder of the Squamata based on morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
characteristics, however molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha
Anguimorpha
Anguimorphs of the infraorder Anguimorpha include the anguids , monitor lizards, the extinct mosasaurs, and helodermatids . The infraorder was named by Fürbringer in 1900 to include all autarchoglossans closer to Varanus and Anguis than Scincus...
and closely related to snakes. They are largely arboreal and have primitively fleshy, non-prehensile tongues, but this condition is obviously highly modified in the chameleons. Traditionally, the clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
includes the following families::
- Family AgamidaeAgamidaeAgamids, lizards of the family Agamidae, include more than 300 species in Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Phylogenetically they may be sister to the Iguanidae, and have a similar appearance. Agamids usually have...
– Agamid Lizards, Old World Arboreal Lizards - Family Chamaeleonidae – Chameleons
- Family CorytophanidaeCorytophanidaeCorytophanidae is a family of lizards also called casque head lizards or helmeted lizards. They typically have well-developed head crests in the shape of a casque. This crest is a sexually dimorphic characteristic in males of Basiliscus, but is present in both sexes of Corytophanes and Laemanctus...
– Helmet Lizards - Family CrotaphytidaeCrotaphytidaeThe family Crotaphytidae, or collared lizards, are desert-dwelling reptiles native to the southwest USA and northern Mexico. They are very fast-moving animals, with long limbs and tails, and are carnivorous, feeding mainly on insects....
– Collared Lizards, Leopard Lizards - Family HoplocercidaeHoplocercidaeFamily Hoplocercidae, or the hoplocercids, are a family of lizards native to the tropical forests of Central and South America. There are ten described species in three genera...
– Dwarf and Spiny Tail Iguanas - Family IguanidaeIguanidaeIguanidae is a family of lizards, composed of iguanas and related species.-Classification of Iguanidae:Two different classification schemes have been used to define the structure of this family. These are the "traditional" classification and the classification presented by Frost et al. .Frost et...
– American Arboreal Lizards, Chuckwallas, Iguanas - Family OpluridaeOpluridaeThe Opluridae, or Madagascan iguanas, are a family of moderately sized lizards native to Madagascar. There are seven species in two genera, with most of the species being in Oplurus. The family includes species that live amongst rocks, some that live in trees, and one that inhabits sand dunes...
– Malagasy Iguanas - Family PhrynosomatidaePhrynosomatidaePhrynosomatidae is a diverse family of lizards, found from Panama to the extreme south of Canada. Many members of the group are adapted to life in hot, sandy deserts, although the spiny lizards prefer rocky deserts or even relatively moist forest edges, and the short-horned lizard lives in prairie...
– North American Spiny Lizards - Family PolychrotidaePolychrotidaePolychrotidae is a family of lizards commonly known as anoles . NCBI places the anole in subfamily Polychrotinae of the family Iguanidae. Four genera are common: Anolis, Norops, Phenacosaurus, and Polychrus....
– Anoles and kin - Family TropiduridaeTropiduridaeThe Tropiduridae is a family of iguanid lizards native to South America and the West Indies. Commonly known as Neotropical ground lizards, most are ground-dwelling animals, and the family includes some lizards adapted to relatively cold climates, including those of the Andes mountains and Tierra...
– Tropidurid Lizards
Extinct:
- Pleurodonta
- Saichangurvel
More recently, a revised delimitation of families is proposed to be more phylogenetically accurate. Most notably, this reduces the Iguanidae to a core set of taxa, upranking many of its former subfamilies to full iguanian families. See Iguanidae
Iguanidae
Iguanidae is a family of lizards, composed of iguanas and related species.-Classification of Iguanidae:Two different classification schemes have been used to define the structure of this family. These are the "traditional" classification and the classification presented by Frost et al. .Frost et...
article for further information.