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.
Ceratonykus is a monospecific genus of alvarezsaurid dinosaur from Mongolia that lived during the Late Cretaceous in what is now the Barun Goyot Formation. The type and only species, Ceratonykus oculatus, is known from a fragmentary skeleton, including an incomplete skull, of an adult individual. It was named and described in 2009 by Vladimir Alifanov and Rinchen Barsbold. Its describers questioned the traditional placement of alvarezsaurs in Theropoda, instead suggesting they were ornithischians, but this has not been accepted since. Ceratonykus has an estimated length of 75 centimetres and weight of 760 grams. It has been considered as a possible junior synonym of Parvicursor.
Dorsetisaurus is a genus of extinct lizard, known from the Late Jurassic of North America, and the Late Jurassic-earliest Cretaceous of Europe. The genus was first reported from the Early Cretaceous (Berriasian) Lulworth Formation of the Purbeck Group of Durlston Bay, in Dorset. It has also been reported from the Late Jurassic aged Alcobaça Formation of Portugal, the Aptian-Albian Dzunbain Formation of Mongolia, and the Morrison Formation of Western North America present in stratigraphic zones 2, 4, and 5. It is considered the oldest widely accepted member of Anguimorpha. based on the presence of 11 shared synapomorphies.
Liushusaurus is an extinct genus of lizard described by Susan E. Evans and Yuan Wang in 2010. The genus has a single species, Liushusaurus acanthocaudata, and is known from eight fossils, several of which preserve soft tissue detail. The specimens were found in the Lower Cretaceous aged Yixian Formation of Northeast China. Liushusaurus is one of eight lizards that are known and have been named from the Yixian Formation, part of the diverse Jehol Biota ecosystem.
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.
Ovoo gurvel is an extinct varanid lizard from the Late Cretaceous of Mongolia. It is one of the smallest and earliest monitor lizards. It was described in 2008. Ovoo possesses a pair of small bones in its skull that are not seen in any other lizard.
Aiolosaurus is an extinct genus of monitor lizard from the Late Cretaceous of Mongolia. The type and only species, Aiolosaurus oriens, was named in 2000 from Ukhaa Tolgod, a rich fossil site in the Campanian-age Djadochta Formation.
Paluxysuchus is an extinct genus of neosuchian crocodyliform known from the Early Cretaceous Twin Mountains Formation of north-central Texas. It contains a single species, Paluxysuchus newmani. Paluxysuchus is one of three crocodyliforms known from the Early Cretaceous of Texas, the others being Pachycheilosuchus and an unnamed species referred to as the "Glen Rose Form". Paluxysuchus has a long, flat skull that is probably transitional between the long and narrow skulls of many early neosuchians and the short and flat skulls of later neosuchians.
Gobekko is an extinct genus of gecko or gecko-like lizard from the Late Cretaceous Djadokhta Formation of the Gobi Desert in Mongolia. Gobekko is either a basal member of Gekkota, the group that includes geckos and the legless pygopodid lizards, or a stem-gekkotan outside Gekkota but within the larger group Gekkonomorpha. It is the fourth oldest known member of Gekkonomorpha after Hoburogekko, a gecko from the Early Cretaceous of Mongolia, AMNH FR21444, an unnamed specimen also from the Early Cretaceous of Mongolia, and Cretaceogekko, a gecko preserved in amber from the Early Cretaceous of Burma.
Gekkonomorpha is a clade of lizards that includes geckos and their closest relatives. Although it was first named in 1900, Gekkonomorpha was not widely used as a formal taxon until it was given a phylogenetic definition in the 1990s. Under this definition, Gekkonomorpha is a stem-based taxon containing the node-based taxon Gekkota, the group that includes the last common ancestor of all living geckos and its descendants. The extent of Gekkonomorpha beyond gekkotans differs between studies. For example, Lee (1998) defined Gekkonomorpha in such a way that it included not only Gekkota but the legless amphisbaenian and dibamid lizards as well. The phylogenetic analysis of Conrad (2008), which did not support a close relationship between geckos and legless lizards, used Gekkonomorpha in a much more restrictive sense so that it included only Gekkota and a few extinct lizards more closely related to Gekkota than to any other living group of lizards. Some of the most recent phylogenetic analyses suggest that the extinct lizards Gobekko and Parviraptor may be stem gekkotans, although other analyses find that Gobekko may instead be within Gekkota and Parviraptor outside Gekkonomorpha.
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.
Saichangurvel is an extinct genus of iguanian lizards from the Late Cretaceous of Mongolia. It is a member of a clade called Gobiguania, an exclusively Late Cretaceous group of iguanian lizards that was likely endemic to the Gobi Desert. The type species, Saichangurvel davidsoni, was named by paleontologists Jack Conrad and Mark Norell of the American Museum of Natural History in 2007. It is known from a single nearly complete and fully articulated skeleton called IGM 3/858, which was found eroding from a block of sandstone during a thunderstorm at a fossil locality called Ukhaa Tolgod. IGM 3/858 comes from the Djadochta Formation, which is between 75 and 71 million years in age. Just as it is today, the Gobi was a desert during the Cretaceous. IGM 3/858 may have died in a collapsing sand dune, the rapid burial preserving its skeleton in pristine condition.
Anchaurosaurus is an extinct genus of iguanian lizard from the Late Cretaceous of Inner Mongolia, China. It belongs to an extinct clade of iguanians called Gobiguania that was endemic to the Gobi Desert during the Late Cretaceous. The type species, Anchaurosaurus gilmorei, was named in 1995 on the basis of a well-preserved skull and incomplete skeleton from the Djadochta Formation. Compared to other iguanians, Anchaurosaurus has a relatively elongated skull, large eye sockets, and higher tooth crowns. Phylogenetic analysis indicates that among gobiguanians, Anchaurosaurus is most closely related to Zapsosaurus from Mongolia. Below is a cladogram from Daza et al. (2012) showing the phylogenetic relationships of Anchaurosaurus:
Polrussia is an extinct genus of iguanian lizards dating to the Late Cretaceous epoch, found in what is now Mongolia. It belongs to a group of extinct iguanians called Gobiguania that was endemic to the Gobi Desert during the Late Cretaceous. The type species Polrussia mongoliensis was named in 1991 on the basis of a skull found in the Barun Goyot Formation. The genus name refers to the Polish and Russian paleontologists who worked together to find and describe the material. Polrussia has a short skull, slightly pointed and flattened snout, and large eye sockets. The teeth each have one cusp, as opposed to the multiple cusps seen in some other gobiguanians. The skull is only 1.2 centimetres (0.47 in) long, making Polrussia one of the smallest gobiguanians.
Igua is an extinct genus of iguanian lizards belonging to a group called Gobiguania that was endemic to the Gobi Desert during the Late Cretaceous. The type species Igua minuta was named in 1991 on the basis of a skull from the Barun Goyot Formation in Mongolia. The skull itself is very small, only 14 millimetres (0.55 in) long, and may have belonged to a juvenile given that it possesses a large fontanelle and that many of the bones are unfused. The snout-vent length of the individual is estimated to have been 55 to 65 millimetres. Igua differs from related gobiguanians like Polrussia in having a more rounded skull. It is similar in appearance to the living genera Liolaemus and Tropidurus. The teeth are tricuspid and pleurodont, meaning they are attached to inner surfaces of the jaws.
Norellius is an extinct genus of scleroglossan lizard from the Early Cretaceous Öösh Formation of Mongolia. It is known from a well-preserved skull that was collected by an American Museum of Natural History expedition to Mongolia in 1923 and cataloged as AMNH FR 21444. After its initial cataloging, the specimen was not mentioned again in the scientific literature until 2004, when it was recognized as belonging to a potential early relative of modern groups of squamates such as gekkotans, amphisbaenians, dibamids, and snakes. AMNH FR 21444 was more fully described in a 2006 study that used high-resolution computed tomography to examine the skull and its braincase, and was described as a new genus and species, Norellius nyctisaurops, in 2015. The genus name honors paleontologist Mark Norell. The 2006 study incorporated the specimen into a phylogenetic analysis and found it to be a basal member of an evolutionary grouping called Gekkonomorpha, a stem-based taxon that includes living geckos and legless lizards (pygopodids) and all taxa more closely related to them than to any other living lizard. Norellius lies outside the node-based taxon Gekkota, a more strictly-defined subgroup of Gekkonomorpha that includes geckos, pygopodids, and all descendants of their most recent common ancestor. Therefore, while Norellius is more closely related to geckos and pygopodids than it is to any other living group of lizards, it branched off before the most recent common ancestor of these two groups. Below is a cladogram showing the position of Norellius according to this phylogeny:
Eichstaettisaurus is a genus of lizards from the Late Jurassic and Early Cretaceous of Germany, Spain, and Italy. With a flattened head, forward-oriented and partially symmetrical feet, and tall claws, Eichstaettisaurus bore many adaptations to a climbing lifestyle approaching those of geckoes. The type species, E. schroederi, is among the oldest and most complete members of the Squamata, being known by one specimen originating from the Tithonian-aged Solnhofen Limestone of Germany. A second species, E. gouldi, was described from another skeleton found in the Matese Mountains of Italy. Despite being very similar to E. schroederi, it lived much later, during the Albian stage. Fossils of both species show exceptional preservation due to deposition in low-oxygen marine environments.
Yuornis is an extinct genus of enantiornithine bird known from the Late Cretaceous of Henan, China. It contains one species, Yuornis junchangi, named after the late Lü Junchang.
Slavoia is an extinct genus of lizard from the Early Cretaceous of Mongolia, and Late Cretaceous of Kazakhstan and Mongolia.
