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Superregnum: Eukaryota
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Cladus: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Infraclassis: Lepidosauromorpha
Superordo: Lepidosauria
Ordo: Squamata
Clades (7): Dibamia – Gekkota – Scincomorpha – Laterata – Iguania – Anguimorpha – Serpentes
[circumscription following Burbrink et al. (2020)]
Genera incertae sedis: †Chmoetokadmon – †Eolacerta – †Hongshanxi – †Jucaraseps – †Liushusaurus – †Megachirella – †Meyasaurus – †Sakurasaurus – †Scandensia – †Yabeinosaurus


Squamata Oppel, 1811: 14
Primary references

Oppel, M. 1811. Die Ordnungen, Familien und Gattungen der Reptilien als Prodrom einer Naturgeschichte derselben. Joseph Lindauer: München. XII + 86 pp. BHL Reference page.

Additional references

Camp, C.L. 1923. Classification of the lizards. Bulletin of the American Museum of Natural History 48: 289–480. hdl: 2246/898 Open access Reference page.
Townsend, T.M., Larson, A., Louis, E. & Macey, J.R. 2004. Molecular phylogenetics of Squamata: The position of snakes, amphisbaenians, and dibamids, and the root of the squamate tree. Systematic Biology 53(5): 735–757. DOI: 10.1080/10635150490522340 Open access Reference page.
Vidal, N. & Hedges, S.B. 2005. The phylogeny of squamate reptiles (lizards, snakes, and amphisbaenians) inferred from nine nuclear protein-coding genes. Comptes Rendus Biologies 328(10–11): 1000–1008. DOI: 10.1016/j.crvi.2005.10.001 Paywall Reference page.
Conrad, J.L. 2008. Phylogeny and systematics of squamata (Reptilia) based on morphology . Bulletin of the American Museum of Natural History 310: 1–182. hdl: 2246/5915 Open access Reference page.
Vidal, N. & Hedges, S.B. 2009. The molecular evolutionary tree of lizards, snakes, and amphisbaenians. Comptes Rendus Biologies 332(2-3): 129–139. DOI: 10.1016/j.crvi.2008.07.010 Open access Reference page.
Wiens, J.J., Kuczynski, C.A., Townsend, T., Reeder, T.W., Mulcahy, D.G. & Sites Jr., J.W. 2010. Combining Phylogenomics and Fossils in Higher-Level Squamate Reptile Phylogeny: Molecular Data Change the Placement of Fossil Taxa. Systematic Biology 59(6): 674–688. DOI: 10.1093/sysbio/syq048 Open access Reference page.
Losos, J.B., Hillis, D.M. & Greene, H.W. 2012. Evolution. Who speaks with a forked tongue? Science 338(6113): 1428–1429. DOI: 10.1126/science.1232455 Paywall Reference page.
Gauthier, J.A., Kearney, M., Maisano, J.A., Rieppel, O. & Behlke, A.D.B. 2012. Assembling the Squamate Tree of Life: Perspectives from the Phenotype and the Fossil Record. Bulletin of the Peabody Museum of Natural History 53(1): 3–308. DOI: 10.3374/014.053.0101 Paywall Reference page.
Wiens, J.J., Hutter, C.R., Mulcahy, D.G., Noonan, B.P., Townsend, T.M., Sites, J.W. & Reeder, T.W. 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 Open access Reference page.
Pyron, R.A., Burbrink, F.T. & Wiens, J.J. 2013. A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology 13: 93. DOI: 10.1186/1471-2148-13-93 Open access Reference page.
Reeder, T.W., Townsend, T.M., Mulcahy, D.G., Noonan, B.P., Wood Jr., P.L., Sites Jr., J.W. & Wiens, J.J. 2015. Integrated analyses resolve conflicts over squamate reptile phylogeny and reveal unexpected placements for fossil taxa. PLoS One 10: e0118199. DOI: 10.1371/journal.pone.0118199 Open access Reference page.
Zheng, Y. & Wiens, J.J. 2016. Combining phylogenomic and supermatrix approaches, and a time-calibrated phylogeny for squamate reptiles (lizards and snakes) based on 52 genes and 4162 species. Molecular Phylogenetics and Evolution 94(Part B): 537–547. DOI: 10.1016/j.ympev.2015.10.009 Paywall Reference page.
Pyron, R.A. 2017. Novel Approaches for Phylogenetic Inference from Morphological Data and Total-Evidence Dating in Squamate Reptiles (Lizards, Snakes, and Amphisbaenians). Systematic Biology 66(1): 38–56. DOI: 10.1093/sysbio/syw068 Open access Reference page.
Streicher, J.W. & Wiens, J.J. 2017. Phylogenomic analyses of more than 4000 nuclear loci resolve the origin of snakes among lizard families. Biology Letters 13(9): 20170393. DOI: 10.1098/rsbl.2017.0393 Open access Reference page.
Burbrink, F.T., Grazziotin, F.G., Pyron, R.A., Cundall, D., Donnellan, S., Irish, F., Keogh, J.S., Kraus, F., Murphy, R.W., Noonan, B., Raxworthy, C.J., Ruane, S., Lemmon, A.R., Lemmon, E.M. & Zaher, H. 2020. Interrogating Genomic-Scale Data for Squamata (Lizards, Snakes, and Amphisbaenians) Shows no Support for Key Traditional Morphological Relationships. Systematic Biology 69(3): 502–520. DOI: 10.1093/sysbio/syz062 Open access Reference page.

Vernacular names
беларуская: Лускаватыя
čeština: Šupinatí
Deutsch: Schuppenkriechtiere
English: Scaled Reptiles
español: Escamosos
français: Squamates
magyar: Pikkelyesbőrűek
հայերեն: Թեփուկավորներ
日本語: 有鱗目
한국어: 유린목(有鱗目), 뱀목
norsk: Skjellkrypdyr
polski: Łuskonośne
português: Escamados
русский: Чешуйчатые
Türkçe: Pullular
українська: Лускаті

Squamata (/skwæˈmeɪtə/, Latin squamatus (“scaly, having scales”)) is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species,[3] it is also the second-largest order of extant (living) vertebrates, after the perciform fish. Members of the order are distinguished by their skins, which bear horny scales or shields. They also possess movable quadrate bones, making possible movement of the upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very wide to accommodate comparatively large prey. Squamata is the most variably sized order of reptiles, ranging from the 16 mm (0.63 in) dwarf gecko (Sphaerodactylus ariasae) to the 5.21 m (17.1 ft) green anaconda (Eunectes murinus) and the now-extinct mosasaurs, which reached lengths over 14 m (46 ft).

Among other reptiles, squamates are most closely related to the tuatara, which superficially resembles lizards.

Slavoia darevskii, a fossil squamate

Squamates are a monophyletic sister group to the rhynchocephalians, members of the order Rhynchocephalia. The only surviving member of the Rhynchocephalia is the tuatara. Squamata and Rhynchocephalia form the subclass Lepidosauria, which is the sister group to the Archosauria, the clade that contains crocodiles and birds, and their extinct relatives. Fossils of rhynchocephalians first appear in the Early Triassic, meaning that the lineage leading to squamates must have also existed at the time.[4] Scientists believe crown group squamates probably originated in the Early Jurassic based on the fossil record.[4] The first fossils of geckos, skinks, and snakes appear in the Middle Jurassic.[5] Other groups like iguanians and varanoids appeared in the Cretaceous. Polyglyphanodontia, an extinct clade of lizards, and mosasaurs, a group of predatory marine lizards that grew to enormous sizes, also appeared in the Cretaceous.[6] Squamates suffered a mass extinction at the Cretaceous–Paleogene (K–PG) boundary, which wiped out polyglyphanodontians, mosasaurs, and many other distinct lineages.[7]

The relationships of squamates is debatable. Although many of the groups originally recognized on the basis of morphology are still accepted, understanding of their relationships to each other has changed radically as a result of studying their genomes. Iguanians were long thought to be the earliest crown group squamates based on morphological data,[6] but genetic data suggest that geckoes are the earliest crown group squamates.[8] Iguanians are now united with snakes and anguimorphs in a clade called Toxicofera. Genetic data also suggest that the various limbless groups - snakes, amphisbaenians, and dibamids - are unrelated, and instead arose independently from lizards.

A study in 2018 found that Megachirella, an extinct genus of lepidosaurs that lived about 240 million years ago during the Middle Triassic, was a stem-squamate, making it the oldest known squamate. The phylogenetic analysis was conducted by performing high-resolution microfocus X-ray computed tomography (micro-CT) scans on the fossil specimen of Megachirella to gather detailed data about its anatomy. These data were then compared with a phylogenetic dataset combining the morphological and molecular data of 129 extant and extinct reptilian taxa. The comparison revealed Megachirella had certain features that are unique to squamates. The study also found that geckos are the earliest crown group squamates, not iguanians.[9][10]
See also: Sexual selection in scaled reptiles
Trachylepis maculilabris skinks mating

The male members of the group Squamata have hemipenes, which are usually held inverted within their bodies, and are everted for reproduction via erectile tissue like that in the mammalian penis.[11] Only one is used at a time, and some evidence indicates that males alternate use between copulations. The hemipenis has a variety of shapes, depending on the species. Often it bears spines or hooks, to anchor the male within the female. Some species even have forked hemipenes (each hemipenis has two tips). Due to being everted and inverted, hemipenes do not have a completely enclosed channel for the conduction of sperm, but rather a seminal groove that seals as the erectile tissue expands. This is also the only reptile group in which both viviparous and ovoviviparous species are found, as well as the usual oviparous reptiles. Some species, such as the Komodo dragon, can reproduce asexually through parthenogenesis.[12]
The Japanese striped snake has been studied in sexual selection.

Studies have been conducted on how sexual selection manifests itself in snakes and lizards. Snakes use a variety of tactics in acquiring mates.[13][dubious – discuss] Ritual combat between males for the females with which they want to mate includes topping, a behavior exhibited by most viperids, in which one male twists around the vertically elevated fore body of his opponent and forcing it downward. Neck biting commonly occurs while the snakes are entwined.[14]
Facultative parthenogenesis
The effects of central fusion and terminal fusion on heterozygosity

Parthenogenesis is a natural form of reproduction in which the growth and development of embryos occur without fertilization. Agkistrodon contortrix (copperhead snake) and Agkistrodon piscivorus (cottonmouth snake) can reproduce by facultative parthenogenesis; they are capable of switching from a sexual mode of reproduction to an asexual mode.[15] The type of parthenogenesis that likely occurs is automixis with terminal fusion (see figure), a process in which two terminal products from the same meiosis fuse to form a diploid zygote. This process leads to genome-wide homozygosity, expression of deleterious recessive alleles, and often to developmental abnormalities. Both captive-born and wild-born A. contortrix and A. piscivorus appear to be capable of this form of parthenogenesis.[15]

Reproduction in squamate reptiles is ordinarily sexual, with males having a ZZ pair of sex-determining chromosomes, and females a ZW pair. However, the Colombian rainbow boa, Epicrates maurus, can also reproduce by facultative parthenogenesis, resulting in production of WW female progeny.[16] The WW females are likely produced by terminal automixis.
Inbreeding avoidance

When female sand lizards mate with two or more males, sperm competition within the female's reproductive tract may occur. Active selection of sperm by females appears to occur in a manner that enhances female fitness.[17] On the basis of this selective process, the sperm of males that are more distantly related to the female are preferentially used for fertilization, rather than the sperm of close relatives.[17] This preference may enhance the fitness of progeny by reducing inbreeding depression.
Evolution of venom
Main article: Evolution of snake venom
See also: Venom

Recent research suggests that the evolutionary origin of venom may exist deep in the squamate phylogeny, with 60% of squamates placed in this hypothetical group called Toxicofera. Venom has been known in the clades Caenophidia, Anguimorpha, and Iguania, and has been shown to have evolved a single time along these lineages before the three groups diverged, because all lineages share nine common toxins.[18] The fossil record shows the divergence between anguimorphs, iguanians, and advanced snakes dates back roughly 200 million years ago (Mya) to the Late Triassic/Early Jurassic,[18] but the only good fossil evidence is from the Middle Jurassic.[1]

Snake venom has been shown to have evolved via a process by which a gene encoding for a normal body protein, typically one involved in key regulatory processes or bioactivity, is duplicated, and the copy is selectively expressed in the venom gland.[19] Previous literature hypothesized that venoms were modifications of salivary or pancreatic proteins,[20] but different toxins have been found to have been recruited from numerous different protein bodies and are as diverse as their functions.[21]

Natural selection has driven the origination and diversification of the toxins to counter the defenses of their prey. Once toxins have been recruited into the venom proteome, they form large, multigene families and evolve via the birth-and-death model of protein evolution,[22] which leads to a diversification of toxins that allows the ambush predators the ability to attack a wide range of prey.[23] The rapid evolution and diversification is thought to be the result of a predator–prey evolutionary arms race, where both are adapting to counter the other.[24]
Humans and squamates
Bites and fatalities
See also: Snakebite
Map showing the global distribution of venomous snakebites

An estimated 125,000 people a year die from venomous snake bites.[25] In the US alone, more than 8,000 venomous snake bites are reported each year, but only one in 50 million people (five or six fatalities per year in the USA) will die from venomous snake bites.[26][27]

Lizard bites, unlike venomous snake bites, are usually not fatal. The Komodo dragon has been known to kill people due to its size, and recent studies show it may have a passive envenomation system. Recent studies also show that the close relatives of the Komodo, the monitor lizards, all have a similar envenomation system, but the toxicity of the bites is relatively low to humans.[28] The Gila monster and beaded lizards of North and Central America are venomous, but not deadly to humans.

Though they survived the Cretaceous–Paleogene extinction event, many squamate species are now endangered due to habitat loss, hunting and poaching, illegal wildlife trading, alien species being introduced to their habitats (which puts native creatures at risk through competition, disease, and predation), and other anthropogenic causes. Because of this, some squamate species have recently become extinct, with Africa having the most extinct species. Breeding programs and wildlife parks, though, are trying to save many endangered reptiles from extinction. Zoos, private hobbyists, and breeders help educate people about the importance of snakes and lizards.
Classification and phylogeny
Desert iguana from Amboy Crater, Mojave Desert, California

Historically, the order Squamata has been divided into three suborders:

Lacertilia, the lizards
Serpentes, the snakes (see also Ophidia)
Amphisbaenia, the worm lizards

Of these, the lizards form a paraphyletic group,[29] since "lizards" excludes the subclades of snakes and amphisbaenians. Studies of squamate relationships using molecular biology have found several distinct lineages, though the specific details of their interrelationships vary from one study to the next. One example of a modern classification of the squamates is[2][30]




Diplodactylidae Underwood 1954Hoplodactylus pomarii white background.jpg

Pygopodidae Boulenger 1884The zoology of the voyage of the H.M.S. Erebus and Terror (Lialis burtonis).jpg





Sphaerodactylidae Underwood 1954

Phyllodactylidae Phyllodactylus gerrhopygus 1847 - white background.jpg



ScincidaeNatural history of Victoria (Egernia cunninghami).jpg



GerrhosauridaeGerrhosaurus ocellatus flipped.jpg

CordylidaeIllustrations of the zoology of South Africa (Smaug giganteus).jpg


Gymnophthalmidae Merrem 1820PZSL1851PlateReptilia06 Cercosaura ocellata.png

Teiidae Gray 1827Bilder-Atlas zur wissenschaftlich-populären Naturgeschichte der Wirbelthiere (Tupinambis teguixin).jpg


Lacertidae Brockhaus' Konversations-Lexikon (1892) (Lacerta agilis).jpg


Rhineuridae Vanzolini 1951

Bipedidae Taylor 1951Bilder-Atlas zur wissenschaftlich-populären Naturgeschichte der Wirbelthiere (Bipes canaliculatus).jpg

Blanidae Kearney & Stuart 2004Blanus cinereus flipped.jpg

Cadeidae Vidal & Hedges 2008

Trogonophidae Gray 1865

Amphisbaenidae Gray 1865Amphisbaena microcephalum 1847 - white background.jpg


Shinisauridae Ahl 1930 sensu Conrad 2006



VaranidaeZoology of Egypt (1898) (Varanus exanthematicus).png


Helodermatidae Gray 1837Gila monster ncd 2012 white background.jpg






Anguidae Gray 1825


ChamaeleonidaeZoology of Egypt (1898) (Chamaeleo calyptratus).jpg

Agamidae Gray 1827Haeckel Lacertilia (Chlamydosaurus kingii).jpg



IguanidaeStamps of Germany (Berlin) 1977, Cyclura cornuta.jpg

Hoplocercidae Frost & Etheridge 1989











Leptotyphlopidae Stejneger 1892Epictia tenella 1847 -white background.jpg

Gerrhopilidae Vidal et al. 2010

Xenotyphlopidae Vidal et al. 2010

Typhlopidae Merrem 1820Typhlops vermicularis3 white background.jpg




Tropidophiidae Brongersma 1951


UropeltidaeUropeltis ceylanica (2) flipped.jpg


CylindrophiidaeCylind resplendens Wagler white background.JPG

Xenopeltidae Bonaparte 1845


Pythonidae Fitzinger 1826Python natalensis Smith 1840 white background.jpg

BoidaeBoa constrictor - 1800-1839 - Print - Iconographia Zoologica - (white background).jpg


Bolyeriidae Hoffstetter 1946


Acrochordidae Bonaparte 1831




ViperidaeIllustrations of the zoology of South Africa (Bitis caudalis).jpg



ColubridaeXenochrophis piscator 1 Hardwicke white background.jpg


ElapidaeBilder-Atlas zur wissenschaftlich-populären Naturgeschichte der Wirbelthiere (Naja naja).jpg

All recent molecular studies[18] suggest that several groups form a venom clade, which encompasses a majority (nearly 60%) of squamate species. Named Toxicofera, it combines the groups Serpentes (snakes), Iguania (agamids, chameleons, iguanids, etc.), and Anguimorpha (monitor lizards, Gila monster, glass lizards, etc.).[18]
List of extant families

The over 10,900 extant squamates are divided into 60 families.

Family Common names Example species Example photo
Gray, 1865
Tropical worm lizards Darwin's worm lizard (Amphisbaena darwinii) Amphisbaenidae - Amphisbaena darwinii.JPG
Taylor, 1951
Bipes worm lizards Mexican mole lizard (Bipes biporus) Bipes biporus.jpg
Blanidae Mediterranean worm lizards Mediterranean worm lizard (Blanus cinereus) Culebra Ciega - panoramio.jpg
Vidal & Hedges, 2008[31]
Cuban worm lizards Cadea blanoides Cadea palirostrata Dickerson 1916.jpg
Vanzolini, 1951
North American worm lizards North American worm lizard (Rhineura floridana) Amphisbaenia 1.jpg
Gray, 1865
Palearctic worm lizards Checkerboard worm lizard (Trogonophis wiegmanni) Trogonophis wiegmanni imported from iNaturalist photo 24355639 on 14 January 2020.jpg
Gekkota (geckos, incl. Dibamia)
Family Common names Example species Example photo
Kluge, 1967
Southern padless geckos Thick-tailed gecko (Underwoodisaurus milii) Thick-tailed Gecko (Underwoodisaurus milii) (8636512143).jpg
Boulenger, 1884
Blind lizards Dibamus nicobaricum Anelytropsis.jpg
Underwood, 1954
Australasian geckos Golden-tailed gecko (Strophurus taenicauda) Golden Tailed Gecko.jpg
Boulenger, 1883
Eyelid geckos Common leopard gecko (Eublepharis macularius) Eublepharis macularius1.jpg
Gray, 1825
Geckos Madagascar giant day gecko (Phelsuma grandis) Madagascar giant day gecko (Phelsuma grandis) Nosy Komba.jpg
Gamble et al., 2008
Geckos Moorish gecko (Tarentola mauritanica) Konstantinos Kalaentzis Tarentola mauritanica (A1).jpg
Boulenger, 1884
Flap-footed lizards Burton's snake lizard (Lialis burtonis) Lialis burtonis.jpg
Underwood, 1954
Geckos Fantastic least gecko (Sphaerodactylus fantasticus) Sphaerodactylus fantasticus fantasticus (51113243252).jpg
Family Common names Example species Example photo
Spix, 1825
Agamas Eastern bearded dragon (Pogona barbata) Bearded dragon04.jpg
Gray, 1825
Chameleons Veiled chameleon (Chamaeleo calyptratus) Chamaelio calyptratus.jpg
Frost & Etheridge, 1989
Casquehead lizards Plumed basilisk (Basiliscus plumifrons) Plumedbasiliskcele4 edit.jpg
Frost & Etheridge, 1989
Collared and leopard lizards Common collared lizard (Crotaphytus collaris) Collared lizard in Zion National Park.jpg
Fitzinger, 1843
Anoles Carolina anole (Anolis carolinensis) Anolis carolinensis.jpg
Frost & Etheridge, 1989
Wood lizards or clubtails Enyalioides binzayedi Holotype of Enyalioides binzayedi - ZooKeys-277-069-g007-top.jpg
Iguanidae Iguanas Marine iguana (Amblyrhynchus cristatus) Marineiguana03.jpg
Frost & Etheridge, 1989
Curly-tailed lizards Hispaniolan masked curly-tailed lizard (Leiocephalus personatus) Leiocephalus-personatus-maskenleguan.jpg
Frost et al., 2001
Leiosaurid lizards Enyalius bilineatus Enyalius bilineatus no Parque Estadual de Caparao por Lucas Rosado (08).jpg
Frost & Etheridge, 1989
Swifts Shining tree iguana (Liolaemus nitidus) Atacama lizard1.jpg
Frost & Etheridge, 1989
Malagasy iguanas Chalarodon madagascariensis Chalarodon madagascariensis male.jpg
Frost & Etheridge, 1989
Earless, spiny, tree, side-blotched and horned lizards Greater earless lizard (Cophosaurus texanus) Reptile tx usa.jpg
Frost & Etheridge, 1989
Bush anoles Brazilian bush anole (Polychrus acutirostris) Polychrus acutirostris.JPG
Frost & Etheridge, 1989
Neotropical ground lizards Microlophus peruvianus Mperuvianus.jpg
Lacertoidea (excl. Amphisbaenia)
Family Common Names Example Species Example Photo
Goicoechea, Frost, De la Riva, Pellegrino, Sites Jr., Rodrigues, & Padial, 2016
Alopoglossid lizards Alopoglossus vallensis Ptychoglossus vallensis.jpg
Fitzinger, 1826
Spectacled lizards Bachia bicolor Bachia bicolor.jpg
Oppel, 1811
Wall lizards Ocellated lizard (Lacerta lepida) Perleidechse-20.jpg
Teiidae Tegus and whiptails Gold tegu (Tupinambis teguixin) Goldteju Tupinambis teguixin.jpg
Family Common names Example species Example photo
Oppel, 1811
Glass lizards, alligator lizards and slowworms Slowworm (Anguis fragilis) Anguidae.jpg
Gray, 1852
American legless lizards California legless lizard (Anniella pulchra) Anniella pulchra.jpg
Helodermatidae Beaded lizards Gila monster (Heloderma suspectum)
Cope, 1866
Knob-scaled lizards Mexican knob-scaled lizard (Xenosaurus grandis) Xenosaurus grandis.jpg
Paleoanguimorpha or Varanoidea
Family Common names Example species Example photo
Lanthanotidae Earless monitor Earless monitor (Lanthanotus borneensis) Real Lanthanotus borneensis.jpg
Shinisauridae Chinese crocodile lizard Chinese crocodile lizard (Shinisaurus crocodilurus) Chin-krokodilschwanzechse-01.jpg
Varanidae Monitor lizards Perentie (Varanus giganteus) Perentie Lizard Perth Zoo SMC Spet 2005.jpg
Family Common Names Example Species Example Photo
Cordylidae Girdled lizards Girdle-tailed lizard (Cordylus warreni) Cordylus breyeri1.jpg
Gerrhosauridae Plated lizards Sudan plated lizard (Gerrhosaurus major) Gerrhosaurus major.jpg
Oppel, 1811
Skinks Western blue-tongued skink (Tiliqua occipitalis) Tiliqua occipitalis.jpg
Xantusiidae Night lizards Granite night lizard (Xantusia henshawi) Xantusia henshawi.jpg
Family Common names Example species Example photo
Bonaparte, 1831[32]
File snakes Marine file snake (Acrochordus granulatus) Wart snake 1.jpg
Stejneger, 1907[33]
Coral pipe snakes Burrowing false coral (Anilius scytale) False Coral Snake (Anilius scytale) close-up (13929278050).jpg
Cundall, Wallach and Rossman, 1993.[34]
Dwarf pipe snakes Leonard's pipe snake, (Anomochilus leonardi) Anomochilus weberi.jpg
Gray, 1825[32] (incl. Calabariidae)
Boas Amazon tree boa (Corallus hortulanus) Corallushortulanus.png
Hoffstetter, 1946
Round Island boas Round Island burrowing boa (Bolyeria multocarinata) Round Island Boa.jpeg
Oppel, 1811[32] sensu lato (incl. Dipsadidae, Natricidae, Pseudoxenodontidae)
Colubrids Grass snake (Natrix natrix) Natrix natrix (Marek Szczepanek).jpg
Fitzinger, 1843
Asian pipe snakes Red-tailed pipe snake (Cylindrophis ruffus) Cylindrophis rufus.jpg
Boie, 1827[32]
Cobras, coral snakes, mambas, kraits, sea snakes, sea kraits, Australian elapids King cobra (Ophiophagus hannah) Ophiophagus hannah2.jpg
Bonaparte, 1845
Indo-Australian water snakes, mudsnakes, bockadams New Guinea bockadam (Cerberus rynchops) HerpetonTentaculatumFord.jpg
Fitzinger, 1843[35]
Lamprophiid snakes Bibron's burrowing asp (Atractaspis bibroni) Lamprophis fuliginosus02.jpg
Cope, 1861
Mexican burrowing snakes Mexican burrowing snake (Loxocemus bicolor) Loxocemus bicolor.jpg
Romer, 1956
Pareid snakes Perrotet's mountain snake (Xylophis perroteti) Xylophis sp. Munnar.jpg
Fitzinger, 1826
Pythons Ball python (Python regius) Ball python lucy.JPG
Brongersma, 1951
Dwarf boas Northern eyelash boa (Trachyboa boulengeri) Cuban Giant Trope (Tropidophis melanurus) (8577519420).jpg
Müller, 1832
Shield-tailed snakes, short-tailed snakes Cuvier's shieldtail (Uropeltis ceylanica) Silybura shortii.jpg
Oppel, 1811[32]
Vipers, pitvipers, rattlesnakes European asp (Vipera aspis) Vipera aspis aspis, Lorraine, France.jpg
Fitzinger, 1826
Odd-scaled snakes and relatives Khase earth snake (Stoliczkia khasiensis) Achalinus formosanus formosanus full body shot.jpg
Gray, 1849
Sunbeam snakes Sunbeam snake (Xenopeltis unicolor) XenopeltisUnicolorRooij.jpg
Scolecophidia (incl. Anomalepidae)
Family Common names Example species Example photo
Taylor, 1939[32]
Dawn blind snakes Dawn blind snake (Liotyphlops beui) Liotyphlops beui.jpg
Vidal et al., 2010[31]
Indo-Malayan blindsnakes Andaman worm snake (Gerrhopilus andamanensis)
Stejneger, 1892[32]
Slender blind snakes Texas blind snake (Leptotyphlops dulcis) Leptotyphlops dulcis.jpg
Merrem, 1820[36]
Blind snakes European blind snake (Typhlops vermicularis) Typhlops vermicularis.jpg
Vidal et al., 2010[31]
Malagasy blind snakes Xenotyphlops grandidieri


Hutchinson, M. N.; Skinner, A.; Lee, M. S. Y. (2012). "Tikiguania and the antiquity of squamate reptiles (lizards and snakes)". Biology Letters. 8 (4): 665–669. doi:10.1098/rsbl.2011.1216. PMC 3391445. PMID 22279152.
Wiens, J. J.; Hutter, C. R.; Mulcahy, D. G.; Noonan, B. P.; Townsend, T. M.; Sites, J. W.; Reeder, T. W. (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.
"Species Numbers (as of May 2021)". Retrieved 28 July 2021.
Jones, Marc E.; Anderson, Cajsa Lipsa; Hipsley, Christy A.; Müller, Johannes; Evans, Susan E.; Schoch, Rainer R. (25 September 2013). "Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara)". BMC Evolutionary Biology. 13: 208. doi:10.1186/1471-2148-13-208. PMC 4016551. PMID 24063680.
Caldwell, Michael W.; Nydam, Randall L.; Alessandro, Palci; Apesteguía, Sebástian (27 January 2015). "The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution". Nature Communications. 6: 5996. Bibcode:2015NatCo...6.5996C. doi:10.1038/ncomms6996. ISSN 2041-1723. PMID 25625704.
Gauthier, Jacques; Kearney, Maureen; Maisano, Jessica Anderson; Rieppel, Olivier; Behlke, Adam D. B. (April 2012). "Assembling the squamate tree of life: perspectives from the phenotype and the fossil record". Bulletin of the Peabody Museum of Natural History. 53: 3–308. doi:10.3374/014.053.0101. S2CID 86355757.
Longrich, Nicholas R.; Bhullar, Bhart-Anjan S.; Gauthier, Jacques (10 December 2012). "Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary". Proceedings of the National Academy of Sciences. 109 (52): 21396–21401. Bibcode:2012PNAS..10921396L. doi:10.1073/pnas.1211526110. PMC 3535637. PMID 23236177.
Pyron, R. Alexander; Burbrink, Frank T.; Wiens, John J. (29 April 2013). "A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes". BMC Evolutionary Biology. 13: 93. doi:10.1186/1471-2148-13-93. PMC 3682911. PMID 23627680.
Simōes, Tiago R.; Caldwell, Michael W.; Talanda, Mateusz; Bernardi, Massimo; Palci, Alessandro; Vernygora, Oksana; Bernardini, Federico; Mancini, Lucia; Nydam, Randall L. (30 May 2018). "The origin of squamates revealed by a Middle Triassic lizard from the Italian Alps". Nature. 557 (7707): 706–709. Bibcode:2018Natur.557..706S. doi:10.1038/s41586-018-0093-3. PMID 29849156. S2CID 44108416.
Weisberger, Mindy (30 May 2018). "This 240-Million-Year-Old Reptile Is the 'Mother of All Lizards'". Live Science. Purch Group. Retrieved 2 June 2018.
"Iguana Anatomy".
Morales, Alex (20 December 2006). "Komodo Dragons, World's Largest Lizards, Have Virgin Births". Bloomberg Television. Retrieved 28 March 2008.
Shine, Richard; Langkilde, Tracy; Mason, Robert T (2004). "Courtship tactics in garter snakes: How do a male's morphology and behaviour influence his mating success?". Animal Behaviour. 67 (3): 477–83. doi:10.1016/j.anbehav.2003.05.007. S2CID 4830666.
Blouin-Demers, Gabriel; Gibbs, H. Lisle; Weatherhead, Patrick J. (2005). "Genetic evidence for sexual selection in black ratsnakes, Elaphe obsoleta". Animal Behaviour. 69 (1): 225–34. doi:10.1016/j.anbehav.2004.03.012. S2CID 3907523.
Booth W, Smith CF, Eskridge PH, Hoss SK, Mendelson JR, Schuett GW (2012). "Facultative parthenogenesis discovered in wild vertebrates". Biol. Lett. 8 (6): 983–5. doi:10.1098/rsbl.2012.0666. PMC 3497136. PMID 22977071.
Booth W, Million L, Reynolds RG, Burghardt GM, Vargo EL, Schal C, Tzika AC, Schuett GW (2011). "Consecutive virgin births in the new world boid snake, the Colombian rainbow Boa, Epicrates maurus". J. Hered. 102 (6): 759–63. doi:10.1093/jhered/esr080. PMID 21868391.
Olsson M, Shine R, Madsen T, Gullberg A, Tegelström H (1997). "Sperm choice by females". Trends Ecol. Evol. 12 (11): 445–6. doi:10.1016/s0169-5347(97)85751-5. PMID 21238151.
Fry, Brian G.; Vidal, Nicolas; Norman, Janette A.; Vonk, Freek J.; Scheib, Holger; Ramjan, S.F. Ryan; et al. (February 2006). "Early evolution of the venom system in lizards and snakes". Nature. 439 (7076): 584–588. doi:10.1038/nature04328. PMID 16292255. S2CID 4386245.
Fry, B. G.; Vidal, N.; Kochva, E.; Renjifo, C. (2009). "Evolution and diversification of the toxicofera reptile venom system". Journal of Proteomics. 72 (2): 127–136. doi:10.1016/j.jprot.2009.01.009. PMID 19457354.
Kochva, E (1987). "The origin of snakes and evolution of the venom apparatus". Toxicon. 25 (1): 65–106. doi:10.1016/0041-0101(87)90150-4. PMID 3564066.
Fry, B. G. (2005). "From genome to "Venome": Molecular origin and evolution of the snake venom proteome inferred from phylogenetic analysis of toxin sequences and related body proteins". Genome Research. 15 (3): 403–420. doi:10.1101/gr.3228405. PMC 551567. PMID 15741511.
Fry, B. G.; Scheib, H.; Young, B.; McNaughtan, J.; Ramjan, S. F. R.; Vidal, N. (2008). "Evolution of an arsenal". Molecular & Cellular Proteomics. 7 (2): 215–246. doi:10.1074/mcp.m700094-mcp200. PMID 17855442.
Calvete, J. J.; Sanz, L.; Angulo, Y.; Lomonte, B.; Gutierrez, J. M. (2009). "Venoms, venomics, antivenomics". FEBS Letters. 583 (11): 1736–1743. doi:10.1016/j.febslet.2009.03.029. PMID 19303875. S2CID 904161.
Barlow, A.; Pook, C. E.; Harrison, R. A.; Wuster, W. (2009). "Coevolution of diet and prey-specific venom activity supports the role of selection in snake venom evolution". Proceedings of the Royal Society B: Biological Sciences. 276 (1666): 2443–2449. doi:10.1098/rspb.2009.0048. PMC 2690460. PMID 19364745.
"Snake-bites: appraisal of the global situation" (PDF). Retrieved 30 December 2007.
"Venomous Snake FAQs". University of Florida. Retrieved 17 September 2019.
"First Aid Snake Bites". University of Maryland Medical Center. Retrieved 30 December 2007.
"Komodo dragon kills boy, 8, in Indonesia". NBC News. Retrieved 30 December 2007.
Reeder, Tod W.; Townsend, Ted M.; Mulcahy, Daniel G.; Noonan, Brice P.; Wood, Perry L.; Sites, Jack W.; Wiens, John J. (2015). "Integrated Analyses Resolve Conflicts over Squamate Reptile Phylogeny and Reveal Unexpected Placements for Fossil Taxa". PLOS ONE. 10 (3): e0118199. doi:10.1371/journal.pone.0118199. PMC 4372529. PMID 25803280.
Zheng, Yuchi; Wiens, John J. (2016). "Combining phylogenomic and supermatrix approaches, and a time-calibrated phylogeny for squamate reptiles (lizards and snakes) based on 52 genes and 4162 species". Molecular Phylogenetics and Evolution. 94 (Part B): 537–547. doi:10.1016/j.ympev.2015.10.009. PMID 26475614.
S. Blair Hedges. "Families described". Hedges Lab | Evolutionary Biology.
Cogger(1991), p.23
"Aniliidae". Integrated Taxonomic Information System. Retrieved 12 December 2007.
"Anomochilidae". Integrated Taxonomic Information System. Retrieved 13 December 2007.
"Atractaspididae". Integrated Taxonomic Information System. Retrieved 13 December 2007.

"Typhlopidae". Integrated Taxonomic Information System. Retrieved 13 December 2007.

Further reading

Bebler, John L.; King, F. Wayne (1979). The Audubon Society Field Guide to Reptiles and Amphibians of North America. New York: Alfred A. Knopf. pp. 581. ISBN 978-0-394-50824-5.
Capula, Massimo; Behler (1989). Simon & Schuster's Guide to Reptiles and Amphibians of the World. New York: Simon & Schuster. ISBN 978-0-671-69098-4.
Cogger, Harold; Zweifel, Richard (1992). Reptiles & Amphibians. Sydney: Weldon Owen. ISBN 978-0-8317-2786-4.
Conant, Roger; Collins, Joseph (1991). A Field Guide to Reptiles and Amphibians Eastern/Central North America. Boston, Massachusetts: Houghton Mifflin Company. ISBN 978-0-395-58389-0.
Ditmars, Raymond L (1933). Reptiles of the World: The Crocodilians, Lizards, Snakes, Turtles and Tortoises of the Eastern and Western Hemispheres. New York: Macmillan. p. 321.
Evans, SE (2003). "At the feet of the dinosaurs: the origin, evolution and early diversification of squamate reptiles (Lepidosauria: Diapsida)". Biological Reviews, Cambridge. 78 (4): 513–551. doi:10.1017/S1464793103006134. PMID 14700390. S2CID 4845536.
Evans SE. 2008. The skull of lizards and tuatara. In Biology of the Reptilia, Vol.20, Morphology H: the skull of Lepidosauria, Gans C, Gaunt A S, Adler K. (eds). Ithaca, New York, Society for the study of Amphibians and Reptiles. pp1–344. Weblink to purchase
Evans, SE; Jones, MEH (2010). The origin, early history and diversification of lepidosauromorph reptiles. In Bandyopadhyay S. (ed.), New Aspects of Mesozoic Biodiversity. 27 Lecture Notes in Earth Sciences. Lecture Notes in Earth Sciences. Vol. 132. pp. 27–44. doi:10.1007/978-3-642-10311-7_2. ISBN 978-3-642-10310-0.
Freiberg, Dr. Marcos; Walls, Jerry (1984). The World of Venomous Animals. New Jersey: TFH Publications. ISBN 978-0-87666-567-1.
Gibbons, J. Whitfield; Gibbons, Whit (1983). Their Blood Runs Cold: Adventures With Reptiles and Amphibians. Alabama: University of Alabama Press. pp. 164. ISBN 978-0-8173-0135-4.
McDiarmid, RW; Campbell, JA; Touré, T (1999). Snake Species of the World: A Taxonomic and Geographic Reference. Vol. 1. Herpetologists' League. p. 511. ISBN 978-1-893777-00-2.
Mehrtens, John (1987). Living Snakes of the World in Color. New York: Sterling. ISBN 978-0-8069-6461-4.
Rosenfeld, Arthur (1989). Exotic Pets. New York: Simon & Schuster. p. 293. ISBN 978-0-671-47654-0.

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