Lizard is the common name used for all squamate reptiles other than snakes, encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The grouping is paraphyletic as some lizards are more closely related to snakes 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.
Squamata is the largest order of reptiles, comprising lizards and snakes. With over 11,500 species, it is also the second-largest order of extant (living) vertebrates, after the perciform fish. Squamates are distinguished by their skins, which bear horny scales or shields, and must periodically engage in molting. 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. Squamates are the most variably sized living reptiles, ranging from the 16 mm (0.63 in) dwarf gecko to the 6.5 m (21 ft) reticulated python. The now-extinct mosasaurs reached lengths over 14 m (46 ft).
Agamidae is a family of over 550 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards.
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 very fast-moving animals, with long limbs and tails; some species are capable of achieving bipedal running at top speed. This species is carnivorous, feeding mainly on insects and smaller lizards. The two genera contain 12 species.
The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana.
Laemanctus is a genus of lizards in the family Corytophanidae. Species in the genus Laemanctus are commonly referred to as conehead lizards or casquehead iguanas. The genus is endemic to Central America.
The common basilisk is a species of lizard in the family Corytophanidae. The species is endemic to Central America and South America, where it is found near rivers and streams in rainforests. It is also known as the Jesus Christ lizard, Jesus lizard, South American Jesus lizard, or lagarto de Jesus Cristo for its ability to run on the surface of water.
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 iguanians are arboreal but there are several terrestrial groups. They usually have primitive fleshy, non-prehensile tongues, although the tongue is highly modified in chameleons. Today they are scattered occurring in Madagascar, the Fiji and Friendly Islands and Western Hemisphere.
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 book Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena. Three species are placed in the genus: the green iguana, which is widespread throughout its range and a popular pet, the marine iguana and the Lesser Antillean iguana, which is native to the Lesser Antilles. Genetic analysis indicates that the green iguana may comprise a complex of multiple species, some of which have been recently described, but the Reptile Database considers all of these as subspecies of the green iguana.
The smooth helmeted iguana, also known as the helmeted iguana, the helmeted basilisk, the elegant helmeted lizard, and several other common names, is a species of Basilisk and a New World lizard in the family Corytophanidae. The species is native to southern Mexico, Central America, and northwestern South America.
The Lamprophiidae are a family of snakes found throughout much of Africa, including the Seychelles. There are 89 species as of July 2022.
Suzanniwana is an extinct genus of iguanian lizards that lived in western North America during the earliest Eocene, approximately 56 million years ago. Two species are known from the Bighorn Basin of Wyoming: the type species S. patriciana named in 2009, and the species S. revenanta named in 2013. Suzanniwana lived during the Paleocene–Eocene Thermal Maximum, a brief period of global warming that resulted in warmer and drier conditions in the Bighorn Basin. It likely stemmed from a lineage that had migrated into the basin from regions farther to the south, following a latitudinal band of constant climatic conditions that moved northward as the planet warmed. Suzanniwana shares many skeletal features with modern casquehead lizards of the family Corytophanidae and may be a stem-corytophanid. It also closely resembles Geiseltaliellus, an iguanian from the middle Eocene Messel pit in Germany.
Babibasiliscus is an extinct genus of casquehead lizard that lived in what is now Wyoming during the early Eocene, approximately 48 million years ago. The genus is known from a single species, Babibasiliscus alxi, which was named by paleontologist Jack Conrad in 2015 on the basis of a fossilized skull from the Bridger Formation in the Green River Basin. The name Babibasiliscus comes from the Shoshoni word babi, meaning "older male cousin", and Basiliscus, a modern-day genus of casquehead lizards. The specimen is undeformed and nearly complete except for the tip of the snout and the top of the skull, making it unclear whether the distinctive bony crest of living corytophanids was present in prehistoric relatives like Babibasiliscus. The skull is about 42 millimetres (2 in) in length and the entire body is estimated to have been about 0.6 metres (2 ft) long. Bones on the right side of lower jaw of the specimen are thickened and fused together, suggesting that the jaw had broken and healed when the animal was alive.
Chamaeleontiformes is a hypothesized clade of iguanian lizards defined as all taxa sharing a more recent common ancestor with Chamaeleo chamaeleon than with Hoplocercus spinosus, Polychrus marmoratus, or Iguana iguana. It was named by paleontologist Jack Conrad in 2008 to describe a clade recovered in his phylogenetic analysis that included the extinct genus Isodontosaurus, the extinct family Priscagamidae, and the living clade Acrodonta, which includes agamids and chameleons. It is a stem-based taxon and one of two major clades within Iguania, the other being Pleurodonta. Below is a cladogram from Daza et al. (2012) showing this phylogeny:
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.
Trachylepis dumasi is a species of skink, a lizard in the family Scincidae. The species is endemic to Madagascar.
Corytophanes hernandesii, also known commonly as Hernandez's helmeted basilisk and el turipache de montaña in Spanish, is a species of lizard in the family Corytophanidae. The species is native to Central America and southern Mexico.
Laemanctus serratus, also known commonly as the serrated casquehead iguana, is a species of lizard in the family Corytophanidae. The species is native to southeastern Mexico and Central America. There are two recognized subspecies.
