lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

iguana ''Iguana'' (, ) is a genus of herbivorous lizards that are native to tropical areas of Mexico, Central America, South America, and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti in his bo ...

chuckwalla Chuckwallas are lizards found primarily in arid regions of the southwestern United States and northern Mexico. Some are found on coastal islands. The six species of chuckwallas are all placed within the genus ''Sauromalus''; they are part of th ...

Crotaphytidae The Crotaphytidae, or collared lizards, are a family of desert-dwelling reptiles native to the Southwestern United States and northern Mexico. Alternatively they are recognized as a subfamily, Crotaphytinae, within the clade Pleurodonta. They are ...

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

Pristiguana ''Pristiguana'' is an extinct genus of primitive iguanids from the Maastrichtian Marília Formation of Brazil.Pariguana'', the two earliest fossil genera, are known from. The subfamily

Iguaninae The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana. Taxonomy Iguanidae is thought to be the sister group to the collared lizards (family Crotaph ...

, which contains all modern genera, likely originated in the earliest

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...

, at about 62 million years ago. The most basal extant genus, ''

Dipsosaurus ''Dipsosaurus'' is a genus of lizards in the family Iguanidae. Taxonomy Currently, there are two described species in this genus. * Desert iguana, ''Dipsosaurus dorsalis'' (Baird and Girard), 1852 * Catalina desert iguana, ''Dipsosaurus cataline ...

,'' diverged from the rest of Iguaninae during the late

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

, about 38 million years ago, with ''

Brachylophus The genus ''Brachylophus'' consists of four extant iguanid species native to the islands of Fiji and a giant extinct species from Tonga in the South West Pacific. One of the extant species, ''B. fasciatus'', is also present on Tonga, where it ha ...

'' following a few million years later at about 35 million years ago, presumably after its dispersal event to the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

. All other modern iguana genera formed in the

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

period. A

phylogenetic tree A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

of Iguaninae is shown here:

Description

Iguanas and iguana-type species are diverse in terms of size, appearance, and habitat. They typically flourish in tropical, warm climates, such as regions of South America and islands in the Caribbean and in the Pacific. Iguanas typically possess dorsal spines across their back, a dewlap on the neck, sharp claws, a long whip-like tail, and a stocky, squat build. Most iguanas are

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

, living in trees, but some species tend to be more

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

, which means they prefer the ground. Iguanas are typically

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

s and their diets vary based on what plant life is available within their habitat. Iguanas across many species remain

oviparious Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

, and exhibit little to no

parental care Parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring. Patterns of parental care are widespread and highly diverse across the animal k ...

when their eggs hatch. They do, however, display nest-guarding behavior. Like all reptiles, they are

poikilotherm A poikilotherm () is an animal whose internal temperature varies considerably. Poikilotherms have to survive and adapt to environmental stress. One of the most important stressors is temperature change, which can lead to alterations in membrane ...

ic, and also rely on regular periods of basking under the sun to

thermoregulate Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

.

Distribution

All but one of modern iguana genera are native to the Americas, ranging from the

deserts A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one ...

of the

Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...

through

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

,

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

, and the

Caribbean The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...

, to throughout

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

down to northernmost

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. Some iguanas like ''I. iguana'' have spread from their native regions of Central and South America into many Pacific Islands, and even to Fiji, Japan, and Hawai'i, due to the exotic pet trade and illegal introductions into the ecosystems. Other iguanas, like the Galapagos pink iguana (''C. marthae'') are endemic only to specific regions on the Galapagos islands. The Grand Cayman blue iguana, ''C. lewisi'', is endemic only to the Grand Cayman island, limited to a small wildlife reserve. The only non-American iguana species are the members of the genus ''

Brachylophus The genus ''Brachylophus'' consists of four extant iguanid species native to the islands of Fiji and a giant extinct species from Tonga in the South West Pacific. One of the extant species, ''B. fasciatus'', is also present on Tonga, where it ha ...

'' and the extinct '' Lapitiguana'', which are found on

Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...

and formerly

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

; their distribution is thought to be the result of the longest overwater dispersal event ever recorded for a vertebrate species, with them rafting over 8000 km across the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

from the

Americas The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. Along with th ...

to the Fiji and Tonga.

Extant genera

Fossils

Classification

Several classification schemes have been used to define the structure of this family. The "historical" classification recognized all New World iguanians, plus ''

Brachylophus The genus ''Brachylophus'' consists of four extant iguanid species native to the islands of Fiji and a giant extinct species from Tonga in the South West Pacific. One of the extant species, ''B. fasciatus'', is also present on Tonga, where it ha ...

'' and the Madagascar oplurines, as informal groups and not as formal subfamilies. Frost and Etheridge (1989) formally recognized these informal groupings as

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...

. 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 In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

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 A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

published to date, recognized most groups at family level, resulting in a narrower definition of Iguanidae.

Historical classification

Family Iguanidae *Informal grouping anoloids: anoles, leiosaurs, ''Polychrus'' *Informal grouping basiliscines: casquehead lizards *Informal grouping crotaphytines: collared and leopard lizards *Informal grouping iguanines: marine, Fijian, Galapagos land, spinytail, rock, desert, green, and chuckwalla iguanas *Informal grouping morunasaurs: wood lizards, clubtails *Informal grouping oplurines: Madagascan iguanids *Informal grouping sceloporines: earless, spiny, tree, side-blotched and horned lizards *Informal grouping tropidurines: curly-tailed lizards, South American swifts, neotropical ground lizards

Frost et al. (1989) classification of iguanas

Family Corytophanidae
Family Crotaphytidae
Family Hoplocercidae
Family Iguanidae *Genus ''

Amblyrhynchus The marine iguana (''Amblyrhynchus cristatus''), also known as the sea iguana, saltwater iguana, or Galápagos marine iguana, is a species of Iguanidae, iguana found only on the Galápagos Islands (Ecuador). Unique among modern lizards, it is a m ...

'' – marine iguana *Genus ''

Brachylophus The genus ''Brachylophus'' consists of four extant iguanid species native to the islands of Fiji and a giant extinct species from Tonga in the South West Pacific. One of the extant species, ''B. fasciatus'', is also present on Tonga, where it ha ...

'' – Fijian/Tongan iguanas *Genus '' Cachryx'' – spinytail iguanas *Genus ''

Conolophus The Galápagos land iguanas comprise the genus ''Conolophus'' of the Galápagos Islands (Ecuador). The number of species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit o ...

'' – Galápagos land iguanas *Genus ''

Ctenosaura ''Ctenosaura'' is a lizard genus commonly known as spinytail iguanas or ctenosaurs. The genus is part of the large lizard family, Iguanidae and is native to Mexico and Central America. The name is derived from two Greek words: ctenos (κτεν ...

'' – spinytail iguanas *Genus ''

Cyclura ''Cyclura'' is a genus of lizards in the family Iguanidae. Member species of this genus are commonly known as "cycluras" or more commonly as rock iguanas and only occur on islands in the West Indies. Rock iguanas have a high degree of endemism, ...

'' – West Indian rock iguanas *Genus ''

Dipsosaurus ''Dipsosaurus'' is a genus of lizards in the family Iguanidae. Taxonomy Currently, there are two described species in this genus. * Desert iguana, ''Dipsosaurus dorsalis'' (Baird and Girard), 1852 * Catalina desert iguana, ''Dipsosaurus cataline ...

'' – desert iguana *Genus ''

Iguana ''Iguana'' (, ) is a genus of herbivorous lizards that are native to tropical areas of Mexico, Central America, South America, and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti in his bo ...

'' – green and Lesser Antillean iguanas *Genus '' Sauromalus'' – chuckwallas *Genus '' Armandisaurus'' (extinct chuckwalla) *Genus '' Lapitiguana'' (extinct giant Fijian iguana) *Genus '' Pumilia'' (extinct Palm Springs iguana) *Genus ''

Pristiguana ''Pristiguana'' is an extinct genus of primitive iguanids from the Maastrichtian Marília Formation of Brazil.Corytophaninae: casquehead lizards *Subfamily Crotaphytinae: collared and leopard lizards *Subfamily Hoplocercinae: wood lizards, clubtails *Subfamily

Iguaninae The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana. Taxonomy Iguanidae is thought to be the sister group to the collared lizards (family Crotaph ...

: marine, Fijian, Galapagos land, spinytail, rock, desert, green, and chuckwalla iguanas *Subfamily Oplurinae: Madagascan iguanids *Subfamily Phrynosomatinae: earless, spiny, tree, side-blotched and horned lizards *Subfamily Polychrotinae: anoles, leiosaurs, ''

Polychrus ''Polychrus'' is the only extant genus of polychrotid lizards in the world. Commonly called bush anoles, they are found in Central and South America, as well as nearby Trinidad and Tobago. ''Polychrus'' means "many colored". True anoles in o ...

'' *Subfamily

Tropidurinae The Tropiduridae are a family of iguanid lizards."Tropiduridae". The Reptile Database. www.reptile-database.org. The family is sometimes considered a subfamily, Tropidurinae. The subfamily is native to South America, including the islands of Tr ...

: curly-tailed lizards, neotropical ground lizards, South American swifts

Schulte et al. (2003) classification of Iguanidae

Here families and subfamilies are proposed as clade names, but may be recognized under the traditional Linnean nomenclature. Iguanidae * Corytophaninae: casquehead lizards * Crotaphytinae: collared and leopard lizards * Hoplocercinae: wood lizards, clubtails *

Iguaninae The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana. Taxonomy Iguanidae is thought to be the sister group to the collared lizards (family Crotaph ...

: marine, Fijian, Galapagos land, spinytail, rock, desert, green, and chuckwalla iguanas * Oplurinae: Madagascan iguanids * Phrynosomatinae: earless, spiny, tree, side-blotched and horned lizards * Polychrotinae: anoles, leiosaurs, ''

Polychrus ''Polychrus'' is the only extant genus of polychrotid lizards in the world. Commonly called bush anoles, they are found in Central and South America, as well as nearby Trinidad and Tobago. ''Polychrus'' means "many colored". True anoles in o ...

'' :*subclade of Polychrotinae ''

Anolis ''Anolis'' is a genus of anoles (), iguanian lizards in the family Dactyloidae, native to the Americas. With more than 425 species, it represents the world's most species-rich amniote tetrapod genus, although many of these have been proposed to ...

'': anoles :*subclade of Polychrotinae Leiosaurini: leiosaurs ::*subclade of Leiosaurini Leiosaurae: ::*subclade of Leiosaurini Anisolepae: :*subclade of Polychrotinae ''

Polychrus ''Polychrus'' is the only extant genus of polychrotid lizards in the world. Commonly called bush anoles, they are found in Central and South America, as well as nearby Trinidad and Tobago. ''Polychrus'' means "many colored". True anoles in o ...

'' : *

Tropidurinae The Tropiduridae are a family of iguanid lizards."Tropiduridae". The Reptile Database. www.reptile-database.org. The family is sometimes considered a subfamily, Tropidurinae. The subfamily is native to South America, including the islands of Tr ...

: curly-tailed lizards, neotropical ground lizards, South American swifts :*subclade of Tropidurinae '' Leiocephalus'': curly-tailed lizards :*subclade of Tropidurinae Liolaemini: South American swifts :*subclade of Tropidurinae Tropidurini: neotropical ground lizards :

Townsend et al. (2011), Wiens et al. (2012) and Pyron et al. (2013) classification of Iguanidae

*Family

Corytophanidae Corytophanidae is a family of iguanian lizards, also called casquehead lizards or helmeted lizards, endemic to the New World. Nine species of casquehead lizards from three genera are recognized. Geographic range Corytophanids are found from Me ...

*Family

Crotaphytidae The Crotaphytidae, or collared lizards, are a family of desert-dwelling reptiles native to the Southwestern United States and northern Mexico. Alternatively they are recognized as a subfamily, Crotaphytinae, within the clade Pleurodonta. They are ...

*Family

Dactyloidae Dactyloidae are a family of lizards commonly known as anoles () and native to warmer parts of the Americas, ranging from southeastern United States to Paraguay. Instead of treating it as a family, some authorities prefer to treat it as a subfam ...

*Family

Hoplocercidae Hoplocercidae are a family of lizards native to the tropical forests, woodlands and savanna-like habitats of Central and South America. Alternatively they are recognized as a subfamily, Hoplocercinae. 20 species in three genera are described. Sp ...

*Family Iguanidae *Family

Leiocephalidae Leiocephalidae, also known as the curlytail lizards or curly-tailed lizards, is a family of iguanian lizards restricted to the West Indies. One of the defining features of these lizards is that their tail often curls over. They were previously ...

*Family

Leiosauridae Leiosauridae is a family of iguanian lizards containing six genera and 34 species. The family is endemic to Central America and South America. Taxonomy A 2022 phylogenetic study found the Leiosauridae to be the sister taxa to the Opluridae, a ...

*Family

Liolaemidae Liolaemidae are a family of iguanian lizards. They are traditionally included in the Iguanidae as subfamily Liolaeminae, which some more recent authors prefer to delimit in a more restricted way. A common name for this group is liolaemids. Liolae ...

*Family

Opluridae The Opluridae, or Madagascan iguanas, are a family of moderately sized lizards native to Madagascar and Grande Comore. There are eight species in two genera, with most of the species being in ''Oplurus''. The Opluridae, along with ''Brachylophus'' ...

*Family

Phrynosomatidae The Phrynosomatidae are a diverse family of lizards, sometimes classified as a subfamily (Phrynosomatinae), 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 ...

*Family

Polychrotidae The Polychrotidae family (sometimes classified as the Polychrotinae subfamily instead) of iguanian lizards contains the living genus ''Polychrus'' (commonly called bush anoles) and the extinct genus ''Afairiguana''. The family Polychrotidae was o ...

*Family

Tropiduridae The Tropiduridae are a family of iguanid lizards."Tropiduridae". The Reptile Database. www.reptile-database.org. The family is sometimes considered a subfamily, Tropidurinae. The subfamily is native to South America, including the islands of Tri ...

References

External links

Family Iguanidae
{{Authority control Taxa named by Nicolaus Michael Oppel Lizard families Extant Early Cretaceous first appearances