| Lizards | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | Lepidosauria |
| Order: | Squamata Günther, 1867 |
This is a list of the extant lizard families. Lizards are an informal group of squamates.
| Lizards | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | Lepidosauria |
| Order: | Squamata Günther, 1867 |
This is a list of the extant lizard families. Lizards are an informal group of squamates.
There are five infraorders which separate the lizards, these are: Diploglossa, Gekkota, Iguania, Platynota and Scincomorpha. This separation is based mainly on morphological similarities between family groups.
The Diploglossans and Platynotans are two closely related infraorders which are very diverse families. Very few generalisations can be placed upon these families morphologically. Many species are limbless, while others have fully formed limbs. It is believed that these lizards are the closest lizard relation to the snakes.
The Gekkotans are the second most diverse group of lizards. They can be morphologically distinguished by the absence of temporal arches, which allows greater moveability of the head. Most species also have cloacal sacs and fixed eyelids.
The Iguanians are another diverse group of lizards. All iguanians are fully limbed. Most species ambush their prey, capture it with their tongue and have skin modification, such as crests and fans, used for many different reasons.
The Scincomorphs are the most diverse group of lizards, accounting for almost half the species of lizards. The major distinguishing morphological feature of the Scincomorphs, is the presence of unsocketed teeth on the inner face of the jaw bones. They also lack the skin modifications present in many of the iguanians. This family contains varying degrees of limb reduction, from completely formed limbs to completely absent of limbs.
As with most taxonomic classifications, there are many different interpretations of the evolutionary relationships. These include moving of families to different infraorders, merging or splitting of the infraorders and merging and splitting of the families.
| Diploglossa | |||
| Family | Common Names | Example Species | Example Photo |
|---|---|---|---|
| Anguidae Oppel, 1811 | Glass lizards | Slowworm (Anguis fragilis) |  |
| Anniellidae Gray, 1852 | American legless lizards | California legless lizard (Anniella pulchra) |  |
| Xenosauridae Cope, 1866 | Knob-scaled lizards | Chinese crocodile lizard (Shinisaurus crocodilurus) |  |
| Gekkota | |||
| Family | Common Names | Example Species | Example Photo |
| Dibamidae Boulenger, 1884 | Blind lizards | Dibamus nicobaricum | - |
| Gekkonidae Gray, 1825 | Geckos | Thick-tailed Gecko (Underwoodisaurus milii) |  |
| Pygopodidae Boulenger, 1884 | Legless lizards | Burton's legless lizard (Lialis burtonis) | - |
| Iguania | |||
| Family | Common Names | Example Species | Example Photo |
| Agamidae Spix, 1825 | Agamas | Eastern bearded dragon (Pogona barbata) |  |
| Chamaeleonidae Gray, 1825 | Chameleons | Veiled chameleon (Chamaeleo calyptratus) |  |
| Corytophanidae Frost & Etheridge, 1989 | Casquehead lizards | Plumed basilisk (Basiliscus plumifrons) |  |
| Crotaphytidae Frost & Etheridge, 1989 | Collared and leopard lizards | Common collared lizard (Crotaphytus collaris) |  |
| Hoplocercidae Frost & Etheridge, 1989 | Wood lizards or clubtails | Club tail iguana (Hoplocercus spinosus) | - |
| Iguanidae | Iguanas | Marine iguana (Amblyrhynchus cristatus) |  |
| Leiosauridae Frost et al., 2001 | - | Darwin's iguana (Diplolaemus darwinii) | - |
| Opluridae Frost & Etheridge, 1989 | Madagascan iguanas | Chalarodon (Chalarodon madagascariensis) | - |
| Phrynosomatidae Frost & Etheridge, 1989 | Earless, spiny, tree, side-blotched and horned lizards | Greater earless lizard (Cophosaurus texanus) |  |
| Polychrotidae Frost & Etheridge, 1989 | Anoles | Caronlina anole (Anolis carolinensis) |  |
| Tropiduridae Frost & Etheridge, 1989 | Neotropical ground lizards | (Microlophus peruvianus) |  |
| Platynota | |||
| Family | Common Names | Example Species | Example Photo |
| Helodermatidae | Gila monsters | Gila Monster (Heloderma suspectum) |  |
| Lanthanotidae | Earless Monitor | Earless Monitor (Lanthanotus borneensis) | - |
| Varanidae | Monitors lizards | Perentie (Varanus giganteus) |  |
| Scincomorpha | |||
| Family | Common Names | Example Species | Example Photo |
| Cordylidae | Spinytail lizards | Girdle-tailed lizard (Cordylus warreni) |  |
| Gerrhosauridae | Plated lizards | Sudan Plated Lizard (Gerrhosaurus major) |  |
| Gymnophthalmidae | Spectacled lizards | - | - |
| Lacertidae Oppel, 1811 | Wall or true lizards | Ocellated Lizard (Lacerta lepida) |  |
| Scincidae Oppel, 1811 | Skinks | Western Blue-tongued Skink (Tiliqua occipitalis) |  |
| Teiidae | Tegus or whiptails | Blue Tegu (Tupinambis teguixin) |  |
| Xantusiidae | Night lizards | Granite Night Lizard (Xantusia henshawi) |  |
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from 1.6 to 60 centimetres.
Lizards are a widespread group of squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic as it excludes the snakes and Amphisbaenia; some lizards are more closely related to these two excluded groups than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3 meter long Komodo dragon.
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes. Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads. To accommodate their narrow bodies, snakes' paired organs appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have evolved elongate bodies without limbs or with greatly reduced limbs about twenty-five times independently via convergent evolution, leading to many lineages of legless lizards. These resemble snakes, but several common groups of legless lizards have eyelids and external ears, which snakes lack, although this rule is not universal.
The even-toed ungulates are ungulates—hoofed animals—which bear weight equally on two of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing posteriorly. By contrast, odd-toed ungulates bear weight on an odd number of the five toes. Another difference between the two is that many other even-toed ungulates digest plant cellulose in one or more stomach chambers rather than in their intestine as the odd-toed ungulates do.
The Lepidosauria is a subclass or superorder of reptiles, containing the orders Squamata and Rhynchocephalia. Squamata includes snakes, lizards, and amphisbaenians. Squamata contains over 9,000 species, making it by far the most species-rich and diverse order of reptiles in the present day. Rhynchocephalia was a formerly widespread and diverse group of reptiles in the Mesozoic Era. However, it is represented by only one living species: the tuatara, a superficially lizard-like reptile native to New Zealand.
Squamata is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians, which are collectively known as squamates or scaled reptiles. With over 10,900 species, 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 to the 6.5 m (21 ft) Reticulated python and the now-extinct mosasaurs, which reached lengths over 14 m (46 ft).
Amphisbaenia is a group of usually legless squamates, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As many species have a pink body and scales arranged in rings, they have a superficial resemblance to earthworms. While the genus Bipes retains forelimbs, all other genera are limbless. Although superficially similar to the snakes and blind lizards, recent phylogenetic studies suggest that they are most closely related to wall lizards of the family Lacertidae. Amphisbaenians are widely distributed, occurring in North America, Europe, Africa, South America, Western Asia and the Caribbean. They are not found east of the Caspian Sea. Most species are less than 6 inches (150 mm) long.
The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana.
Dibamidae or blind skinks is a family of lizards characterized by their elongated cylindrical body and an apparent lack of limbs. Female dibamids are entirely limbless and the males retain small flap-like hind limbs, which they use to grip their partner during mating. They have a rigidly fused skull, lack pterygoid teeth and external ears. Their eyes are greatly reduced, and covered with a scale.
Anguidae refers to a large and diverse family of lizards native to the Northern Hemisphere. Common characteristics of this group include a reduced supratemporal arch, striations on the medial faces of tooth crowns, osteoderms, and a lateral fold in the skin of most taxa. The group includes the slowworms, glass lizards, and alligator lizards, among others. The family is divided into three subfamilies, and contains about 100 species in 10 genera.
Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Skinks are characterized by their smaller legs in comparison to typical lizards and are found in different habitats except arctic and subarctic regions.
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 be moved to other genera, in which case only about 45 Anolis species remain. Previously, it was classified under the family Polychrotidae that contained all the anoles, as well as Polychrus, but recent studies place it in the Dactyloidae.
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, which comprise nearly 11,000 named species, roughly 2000 of which are iguanians. However, molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha and closely related to snakes. 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. Most Iguanias are arboreal but there are several terrestrial groups. They usually have primitive fleshy, non-prehensile tongues, although the tongue is highly modified in chameleons. The group has a fossil record that extends back to the Early Jurassic. Today they are scattered occurring in Madagascar, the Fiji and Friendly Islands and Western Hemisphere
Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises different problems than that in water, with reduced friction being replaced by the increased effects of gravity.
The Anguimorpha is a suborder of squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to Varanus and Anguis than Scincus. These lizards, along with iguanians and snakes, constitute the proposed "venom clade" Toxicofera of all venomous reptiles. The oldest definitive record of the group is Dorsetisaurus from the Late Jurassic of Europe and North America.
Scleroglossa is a group of lizards that includes geckos, autarchoglossans, and amphisbaenians. Scleroglossa is supported by phylogenetic analyses that use morphological features. According to most morphological analyses, Scleroglossa is the sister group of the clade Iguania, which includes iguanas, chameleons, agamids, and New World lizards. Together, Scleroglossa and Iguania make up the crown group Squamata, the smallest evolutionary grouping to include all living lizards and snakes.
The Carphodactylidae, informally known as the southern padless geckos, are a family of geckos, lizards in the infraorder Gekkota. The family consists of 32 described species in 7 genera, all of which are endemic to Australia. They belong to the superfamily Pygopodoidea, an ancient group of east Gondwanan geckos now only found in Australasia. Despite their well-developed limbs, molecular phylogenies have demonstrated that Carphodactylidae is the sister group to Pygopodidae, a highly specialized family of legless lizards.
Anolis grahami, commonly known as the Jamaican turquoise anole or the Graham’s anole, is a species of lizard native to the island of Jamaica, and has now also been introduced to the territory of Bermuda. It is one of many different species of anole lizards found in Jamaica.
Geiseltaliellus is an extinct genus of iguanian lizards that lived in what is now western Europe during the Eocene. It belongs to the family Corytophanidae, which includes modern casquehead lizards. Many fossils are known from Germany, France, and Belgium, with the most well preserved coming from the Messel pit lagerstätte in Messel, Germany. German paleontologist Oskar Kuhn named the genus in 1944 after the Geiseltal valley where the first specimens were found, designating the type species Geiseltaliellus longicaudus. Three new species — G. louisi, G. lamandini, and G. grisolli — were named in the 1990s and 2000s on the basis of more fragmentary remains from France and Belgium, although G. louisi has since been synonymized with G. longicaudus. In 2009 the Messel pit specimens were recognized as belonging to a species distinct from that of the G. longicaudus specimens in Geiseltalt and were collectively reclassified under a new name, G. maarius.