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.
Ankylosaurus is a genus of armored dinosaur. Its fossils have been found in geological formations dating to the very end of the Cretaceous Period, about 68–66 million years ago, in western North America, making it among the last of the non-avian dinosaurs. It was named by Barnum Brown in 1908; the only species in the genus is A. magniventris. The genus name means "fused lizard", and the specific name means "great belly". A handful of specimens have been excavated to date, but a complete skeleton has not been discovered. Though other members of Ankylosauria are represented by more extensive fossil material, Ankylosaurus is often considered the archetypal member of its group, despite having some unusual features.
Scelidosaurus is a genus of herbivorous armoured ornithischian dinosaur from the Jurassic of England.
Aeolosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. Like most sauropods, it would have been a quadrupedal herbivore with a long neck and tail. Aeolosaurus is well known for a titanosaur, as it is represented by the remains of several individuals belonging to at least three species. However, like most titanosaurs, no remains of the skull are known. The holotype of Aeolosaurus rionegrinus consists of a series of seven tail vertebrae, as well as parts of both forelimbs and the right hindlimb. It was discovered in the Angostura Colorada Formation in Argentina, which dates from the Campanian stage of the Late Cretaceous, about 83 to 74 million years ago.
Scutellosaurus is an extinct genus of thyreophoran ornithischian dinosaur that lived approximately 196 million years ago during the early part of the Jurassic Period in what is now Arizona, USA. It is classified in Thyreophora, the armoured dinosaurs; its closest relatives may have been Emausaurus and Scelidosaurus, another armored dinosaur which was mainly a quadrupedal dinosaur, unlike bipedal Scutellosaurus. It is one of the earliest representatives of the armored dinosaurs and the basalmost form discovered to date. Scutellosaurus was a small, lightly-built, ground-dwelling, herbivore, that could grow up to an estimated 1.2 m (3.9 ft) long.
Peltosaurus is an extinct genus of anguid lizard from North America that lived from the Eocene to the Oligocene. Peltosaurus belongs to the anguid subfamily Glyptosaurinae. The type species Peltosaurus granulosus was named in 1873 by American paleontologist Edward Drinker Cope. Many additional species have been named, but most have been reassigned to different genera. For example, Peltosaurus piger, named in 1928, was reclassified as Odaxosaurus piger, and P. jepseni, named in 1942 from the Paleocene of Wyoming, but was later reclassified as Proxestops jepseni. In 1955 a new species, Peltosaurus macrodon, was named from the Eocene of California. Lizard bones from the Late Miocene of Nebraska were attributed to a new species of Peltosaurus called P. minimus in 1976, extending the fossil range of Peltosaurus and Glyptosaurinae into the Neogene. However, these bones were later referred to a genus of skinks called Eumeces, meaning that the fossil range of Peltosaurus and Glyptosaurinae does not go beyond the Paleogene.
Doswellia is an extinct genus of archosauriform from the Late Triassic of North America. It is the most notable member of the family Doswelliidae, related to the proterochampsids. Doswellia was a low and heavily built carnivore which lived during the Carnian stage of the Late Triassic. It possesses many unusual features including a wide, flattened head with narrow jaws and a box-like rib cage surrounded by many rows of bony plates. The type species Doswellia kaltenbachi was named in 1980 from fossils found within the Vinita member of the Doswell Formation in Virginia. The formation, which is found in the Taylorsville Basin, is part of the larger Newark Supergroup. Doswellia is named after Doswell, the town from which much of the taxon's remains have been found. A second species called D. sixmilensis was described in 2012 from the Bluewater Creek Formation of the Chinle Group in New Mexico; however, this species was subsequently transferred to the separate doswelliid genus Rugarhynchos.
Glyptodon was a genus of large, heavily armored mammals of the subfamily Glyptodontinae – relatives of armadillos – that lived during the Pleistocene epoch. It was roughly the same size and weight as a Volkswagen Beetle. With its rounded, bony shell and squat limbs, it superficially resembled a turtle, and the much earlier dinosaurian ankylosaur – providing an example of the convergent evolution of unrelated lineages into similar forms. In 2016 an analysis of Doedicurus mtDNA found it was, in fact, nested within the modern armadillos as the sister group of a clade consisting of Chlamyphorinae and Tolypeutinae. For this reason, glyptodonts and all armadillos but Dasypus were relocated to a new family, Chlamyphoridae, and glyptodonts were demoted from the former family Glyptodontidae to a subfamily.
Proplatynotia is an extinct genus of varanoid lizard from the Late Cretaceous of Mongolia. Fossils have been found in the Barun Goyot Formation, which is mid-Campanian in age. The type and only species, P. longirostratia, was named in 1984.
Saniwa is an extinct genus of varanid lizard that lived about 48 million years ago during the Eocene epoch. It is known from well-preserved fossils found in the Bridger and Green River Formations of Wyoming, and evidence indicates Saniwa also lived in Europe. The type species S. ensidens was described in 1870 as the first fossil lizard known from North America. Several other species have since been added, but their validity is uncertain. It is a close relative of Varanus, the genus that includes monitor lizards.
Bahndwivici is an extinct genus of lizard known from a nearly complete and articulated skeleton discovered in rocks of the Green River Formation of Wyoming, United States. The skeleton is very similar to that of the modern Chinese crocodile lizard, Shinisaurus.
Jaxtasuchus is an extinct genus of armored doswelliid archosauriform reptile known from the Middle Triassic of the Erfurt Formation in Germany. The type species, Jaxtasuchus salomoni, was named in 2013 on the basis of several incomplete skeletons and other isolated remains. Like other doswelliids, members of the genus were heavily armored, with four longitudinal rows of bony plates called osteoderms covering the body. Jaxtasuchus is the first doswelliid known from Europe and is most closely related to Doswellia from the Late Triassic of the eastern United States. However, it was not as specialized as Doswellia, retaining several generalized archosauriform characteristics and having less armor. Jaxtasuchus fossils have been found in aquatic mudstones alongside fossils of temnospondyl amphibians, crustaceans, and mollusks, suggesting that Jaxtasuchus was semiaquatic like modern crocodilians.
Barbaturex is an extinct genus of giant herbivorous iguanian lizards from the Eocene of Myanmar. It is represented by a single species, Barbaturex morrisoni, which is known from several partial dentaries and a fused pair of frontals, two bones that form part of the top of the skull. Based on the size of these bones, Barbaturex morrisoni is estimated to have been about 1 metre (3.3 ft) from snout to vent, and possibly up to 6 feet (1.8 m) including the tail. Barbaturex morrisoni was named after The Doors frontman Jim Morrison, a play on his epithet "The Lizard King". The genus's name is a portmanteau of the Latin words Barbatus and rex, meaning "bearded king", in reference to ridges along the mandible and the lizard's large size.
Hoburogekko is an extinct genus of gecko that includes a single species, Hoburogekko suchanovi, from the Early Cretaceous of Mongolia. It is known from two fossil specimens, one preserving the front part of the skull and the other preserving part of the lower jaw. Hoburogekko is one of four known Mesozoic geckos or gecko-like lizards, the others being Cretaceogekko from the Early Cretaceous of Burma, AMNH FR21444, an undescribed specimen from a slightly older deposit in Mongolia, and Gobekko from the Late Cretaceous of Mongolia. Hoburogekko is the third oldest known gecko behind AMNH FR21444 and Cretaceogekko.
Glyptosaurinae is an extinct subfamily of anguid lizards that lived in the Northern Hemisphere during the Late Cretaceous and the Paleogene.
Myrmecodaptria is an extinct genus of scleroglossan lizard from the Late Cretaceous Djadokhta Formation in Ukhaa Tolgod, Mongolia. The type and only species, Myrmecodaptria microphagosa, was named in 2000 by paleontologists Gao Keqin and Mark Norell. Myrmecodaptria is known from a single holotype skull and lower jaws. It is distinguished from all other lizards by its extremely elongated skull. The eyes are placed close to the snout, which is short and rounded. The top of the skull is covered in bony knobs called osteoderms. The parietal bone at the back of the skull is elongated and about as long as the frontal bones, which are the usually the longest bones along the top of the skull in lizards. The squamosal bone at the back of the skull reaches forward to connect with the jugal bone behind the eye, forming a thin arch between the temporal fenestrae. Myrmecodaptria also has fewer and more widely spaced teeth in its jaws than do most other lizards.
Carusia is an extinct genus of lizards from the Late Cretaceous of Mongolia. It is a close relative of the family Xenosauridae, which includes living knob-scaled lizards. Fossils of the type and only species Carusia intermedia come from the late-Campanian age Barun Goyot Formation and have been found in the Flaming Cliffs, Ukhaa Tolgod, and Kheerman Tsav fossil localities. Carusia was first described in 1985 under the name Carolina intermedia, but since the name Carolina was preoccupied by a genus of scarab beetles that had been named in 1880, it was renamed Carusia intermedia. Carusia had initially been known from fragmentary skull material, complicating efforts to determine its evolutionary relationships with other lizards; it had variously been described as an indeterminate scincomorph, a xenosaurid, or some other type of autarchoglossan lizard convergent with xenosaurids. However, the discovery of 35 complete skulls in the 1990s, three of which were described in a detailed 1998 monograph, revealed that Carusia was the sister taxon of Xenosauridae, compelling the authors of the monograph to create a new clade called Carusioidea to include both taxa.
Osteoderms are dermal bone structures that support the upper layer of skin and serve as protection against the elements in a large variety of extinct and extant organisms, especially reptiles. This structure is commonly called "dermal armor" and serves to protect the organism, while also helping with temperature regulation. Osteoderms represent hard tissue components of the integument, making them easy to identify in fossil examination. This dermal armor is found prominently in many lizards. Some early amphibians have this armor, but it is lost in modern species with the exception a ventral plate, called the gastralia.
Stenoplacosaurus is an extinct genus of glyptosaurine anguid lizards from the Eocene of Inner Mongolia, China. The genus is monotypic, containing only the species Stenoplacosaurus mongoliensis.
Paraplacosauriops is an extinct genus of anguid lizards from the middle Eocene of France.
