The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives,[1] including the widespread green iguana.

Iguanids
Temporal range: Late Cretaceous–Holocene
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Clade: Pleurodonta
Family: Iguanidae
Oppel, 1811
Genera

Amblyrhynchus
Brachylophus
Cachryx
Conolophus
Ctenosaura
Cyclura
Dipsosaurus
Iguana
Sauromalus

Taxonomy

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Iguanidae is thought to be the sister group to the collared lizards (family Crotaphytidae); the two groups likely diverged during the Late Cretaceous, as that is when Pristiguana and Pariguana, the two earliest fossil genera, are known from. The subfamily Iguaninae, which contains all modern genera, likely originated in the earliest Paleocene, at about 62 million years ago. The most basal extant genus, Dipsosaurus, diverged from the rest of Iguaninae during the late Eocene, about 38 million years ago, with Brachylophus following a few million years later at about 35 million years ago, presumably after its dispersal event to the Pacific. All other modern iguana genera formed in the Neogene period.[2]

A phylogenetic tree of Iguaninae is shown here:[2]

Description

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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, living in trees, but some species tend to be more terrestrial, which means they prefer the ground. Iguanas are typically herbivores and their diets vary based on what plant life is available within their habitat. Iguanas across many species remain oviparious, and exhibit little to no parental care when their eggs hatch. They do, however, display nest-guarding behavior. Like all extant non-avian reptiles, they are poikilothermic, and also rely on regular periods of basking under the sun to thermoregulate.[3]

Distribution

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All but one of modern iguana genera are native to the Americas, ranging from the deserts of the Southwestern United States through Mexico, Central America, and the Caribbean, to throughout South America down to northernmost Argentina. 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.[4] 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.[3] The only non-American iguana species are the members of the genus Brachylophus and the extinct Lapitiguana, which are found on Fiji and formerly Tonga; 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 from the Americas to the Fiji and Tonga.[5]

Extant genera

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Image Genus Species
  Amblyrhynchus Bell, 1825 – marine iguana
  Brachylophus Cuvier, 1829 – Fijian/Tongan iguanas
  Cachryx Cope, 1866 – spinytail iguanas
  Conolophus Fitzinger, 1843 – Galápagos land iguanas
  Ctenosaura Wiegmann, 1828 – spiny-tailed iguanas
  Cyclura Harlan, 1825 – West Indian rock iguanas
  Dipsosaurus Hallowell, 1854
  Iguana Laurenti, 1768 – green and Lesser Antillean iguanas
  • Iguana delicatissima — Lesser Antillean iguana Laurenti, 1768
  • Iguana iguana — Green iguana (Linnaeus, 1758)
    • Iguana iguana insularis — Grenadines horned iguana
    • Iguana iguana melanoderma — Saban black iguana
    • Iguana iguana sanctaluciae — St. Lucia Horned Iguana
  Sauromalus Dumeril, 1856 – chuckwallas

Fossils

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Image Genus Species
  Armandisaurus Norell & de Queiroz, 1991
  • Armandisaurus explorator
  Lapitiguana Pregill & Worthy, 2003
  • Lapitiguana impensa
  Pumilia Norell 1989
  • Pumilia novaceki
Pristiguana Estes & Price 1973
  • Pristiguana brasiliensis
Pariguana Longrich et al., 2012
  • Pariguana lancensis

Classification

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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.[6]

Frost and Etheridge (1989) formally recognized these informal groupings as families.[7][8]

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.[9]

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.[10]

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.[11][12][13]

Historical classification

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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

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Family Corytophanidae
Family Crotaphytidae
Family Hoplocercidae
Family Iguanidae

Family Opluridae
Family Phrynosomatidae
Family Polychridae
Family Tropiduridae

Macey et al. (1997) classification of Iguanidae

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Family Iguanidae

Schulte et al. (2003) classification of Iguanidae

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Here families and subfamilies are proposed as clade names, but may be recognized under the traditional Linnean nomenclature.

Iguanidae

  • subclade of Polychrotinae Anolis: anoles
  • subclade of Polychrotinae Leiosaurini: leiosaurs
  • Tropidurinae: 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

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References

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  1. ^ Bauer, Aaron M. (1998). Cogger, H.G.; Zweifel, R.G. (eds.). Encyclopedia of Reptiles and Amphibians. San Diego: Academic Press. pp. 140–142. ISBN 0-12-178560-2.
  2. ^ a b Malone, Catherine L.; Reynoso, Víctor Hugo; Buckley, Larry (2017-10-01). "Never judge an iguana by its spines: Systematics of the Yucatan spiny tailed iguana, Ctenosaura defensor (Cope, 1866)". Molecular Phylogenetics and Evolution. 115: 27–39. doi:10.1016/j.ympev.2017.07.010. ISSN 1055-7903. PMID 28716742.
  3. ^ a b "Anoles, Iguanas, and Relatives: Iguanidae | Encyclopedia.com". www.encyclopedia.com. Retrieved 2021-03-31.
  4. ^ Falcón, Wilfredo; Ackerman, James D.; Recart, Wilnelia; Daehler, Curtis C. (April 2013). "Biology and Impacts of Pacific Island Invasive Species. 10. Iguana iguana , the Green Iguana (Squamata: Iguanidae)". Pacific Science. 67 (2): 157–186. doi:10.2984/67.2.2. ISSN 0030-8870. S2CID 84905657.
  5. ^ Keogh, J. Scott; Edwards, Danielle L; Fisher, Robert N; Harlow, Peter S (2008-10-27). "Molecular and morphological analysis of the critically endangered Fijian iguanas reveals cryptic diversity and a complex biogeographic history". Philosophical Transactions of the Royal Society B: Biological Sciences. 363 (1508): 3413–3426. doi:10.1098/rstb.2008.0120. ISSN 0962-8436. PMC 2607380. PMID 18782726.
  6. ^ Etheridge, Richard; de Queiroz, Kevin (1988). Estes, R.; Pregill, G. (eds.). Phylogenetic Relationships of the Lizard Families, Essays Commemorating Charles L. Camp. Stanford, California: Stanford University Press. pp. 283–368. ISBN 0-8047-1435-5.
  7. ^ D.R. Frost & R. Etheridge (1989) «A phylogenetic analysis and taxonomy of iguanian lizards (Reptilia: Squamata)» Univ. Kansas Mus. Nat. Hist. Misc. Publ. 81
  8. ^ D.R. Frost, R. Etheridge, D. Janies & T.A. Titus (2001) Total evidence, sequence alignment, evolution of polychrotid lizards, and a reclassification of the Iguania (Squamata: Iguania) American Museum Novitates 3343: 38 pp.
  9. ^ Macey J.R., Larson A., Ananjeva N.B., Papenfuss T.J. (1997). "[Evolutionary shifts in three major structural features of the mitochondrial genome among iguanian lizards.]". Journal of Molecular Evolution. 44 (6): 660–674. Bibcode:1997JMolE..44..660M. doi:10.1007/pl00006190. PMID 9169559. S2CID 30106562.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  10. ^ Schulte II J.A., Valladares J.P., Larson A. (2003). "[Phylogenetic relationships within Iguanidae inferred using molecular and morphological data and a phylogenetic taxonomy of iguanian lizards.]". Herpetologica. 59 (3): 399–419. doi:10.1655/02-48. S2CID 56054202.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  11. ^ Townsend; Mulcahy; Noonan; Sites Jr; Kuczynski; Wiens; Reeder (2011). "Phylogeny of iguanian lizards inferred from 29 nuclear loci, and a comparison of concatenated and species-tree approaches for an ancient, rapid radiation". Molecular Phylogenetics and Evolution. 61 (2): 363–380. doi:10.1016/j.ympev.2011.07.008. PMID 21787873.
  12. ^ Wiens; Hutter; Mulcahy; Noonan; Townsend; Sites Jr.; Reeder (2012). "Resolving the phylogeny of lizards and snakes (Squamata) with extensive sampling of genes and species". Biology Letters. 8 (6): 1043–1046. doi:10.1098/rsbl.2012.0703. PMC 3497141. PMID 22993238.
  13. ^ Pyron; Burbrink; Wiens (2013). "A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes". BMC Evolutionary Biology. 13 (1): 93. Bibcode:2013BMCEE..13...93P. doi:10.1186/1471-2148-13-93. PMC 3682911. PMID 23627680.
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