Varanopidae

Varanopidae is an extinct family of amniotes known from the Late Carboniferous to Middle Permian that resembled monitor lizards (with the name of the group deriving from the monitor lizard genus Varanus) and may have filled a similar niche. Typically, they are considered to be relatively basal synapsids (and thus more closely related to mammals than to reptiles), although some studies from the late 2010s recovered them being taxonomically closer to diapsid reptiles; recent studies from the early 2020s support their traditional placement as synapsids on the basis of high degree of bone labyrint

Varanops is an extinct genus of Early Permian varanopid known from Texas and Oklahoma of the United States. It was first named by Samuel Wendell Williston in 1911 as a second species of Varanosaurus, Varanosaurus brevirostris. In 1914, Samuel W. Williston reassigned it to its own genus and the type species is Varanops brevirostris. thumb|Reconstruction of Varanops brevirostris

Varanodon is an extinct genus of amniotes from the family Varanopidae. It has been found in the Chickasha Formation of Oklahoma, which dates to the Roadian stage of the Middle Permian. The largest varanopid known at the time of its description, with a skull length of , it was closely related to and lived alongside its much larger relative Watongia. The two may represent growth stages of a single animal.

left|thumb|159x159px|Life restoration Archaeovenator is an extinct genus of Late Carboniferous varanopid synapsids known from Greenwood County, Kansas of the United States. It was first named by Robert R. Reisz and David W. Dilkes in 2003 and the type species is Archaeovenator hamiltonensis. Archaeovenator hamiltonensis is known from the holotype KUVP 12483, a three-dimensionally preserved, nearly complete and articulated skeleton, including the skull, with limbs and girdles slightly separated from postcranial skeleton. It was collected in the Hamilton Quarry, from the Calhouns Shale Form

Aerosaurus (meaning "copper lizard") is an extinct genus within Varanopidae, a family of non-mammalian synapsids. It lived between 252-299 million years ago during the Early Permian in North America. The name comes from Latin aes (aeris) (combining stem: aer-) “copper” and Greek sauros “lizard,” for El Cobre Canyon (from Spanish cobre “copper”) in northern New Mexico, where the type fossil was found and the site of former copper mines. Aerosaurus was a small to medium-bodied carnivorous synapsid characterized by its recurved teeth, triangular lateral temporal fenestra, and extended teeth row.

Mycterosaurus (Greek as mykter/mykteros meaning nose/snout, sauros meaning "lizard") is an extinct genus of amniotes belonging to the family Varanopidae. It is classified in the varanopid subfamily Mycterosaurinae. Mycterosaurus is the most primitive member of its family, existing from 290.1 to 272.5 MYA, known to Texas and Oklahoma. It lacks some features that its advanced relatives have.

Elliotsmithia is a small varanopid synapsid found from the late Middle Permian of South Africa. It is the sole basal synapsid "pelycosaur" known from the supercontinent Gondwana and only two specimens have been yielded to date. Its species name longiceps is derived from Latin, meaning "long head". Both known Elliotsmithia fossils were recovered from Abrahamskraal Formation rocks—within the boundaries of the Tapinocephalus Assemblage Zone—of the lower Beaufort Group. It was named for the late Sir Grafton Elliot Smith in 1937.

Mesenosaurus is an extinct genus of synapsid belonging to the family Varanopidae. This genus includes two species: the type species Mesenosaurus romeri from the middle Permian (upper Kazanian) Mezen River Basin of northern Russia, and Mesenosaurus efremovi from the early Permian (Artinskian) Richards Spur locality (Oklahoma, United States). M. romeri’s stratigraphic range is the middle to late Guadalupian while M. efremovi’s stratigraphic range is the Cisuralian.

Ascendonanus (meaning "climbing dwarf") is an extinct genus of possible varanopid amniote from the Early Permian of Germany. It is one of the earliest specialized arboreal (tree-living) tetrapods currently known and outwardly resembled a small lizard. The animal was about 40 cm long, with strongly curved claws, short limbs, a slender, elongated trunk, and a long tail. It would have preyed on insects and other small arthropods.

Heleosaurus scholtzi is an extinct species of basal synapsids, known as pelycosaurs, in the family of Varanopidae during the middle Permian. At first H. scholtzi was mistakenly classified as a diapsid. Members of this family were carnivorous and had dermal armor, and somewhat resembled monitor lizards. This family was the most geologically long lived, widespread, and diverse group of early amniotes. To date only two fossils have been found in the rocks of South Africa. One of these fossils is an aggregation of five individuals.

Watongia is an extinct genus of non-mammalian synapsids from Middle Permian of Oklahoma. Only one species has been described, Watongia meieri, from the Chickasha Formation. It was assigned to family Gorgonopsidae by Olson and to Eotitanosuchia by Carroll. Reisz and collaborators assigned the genus in Varanopidae. Based on comparisons of its vertebrae with other varanopids, it was the largest varanopid with a body length of approximately . It was a contemporary of its closest relative, the much smaller Varanodon; the two may possibly represent growth stages of a single animal.

Apsisaurus is an extinct genus of Early Permian varanopid synapsids known from Texas of the United States. It was first named by Michel Laurin in 1991 and the type species is Apsisaurus witteri. Apsisaurus witteri is known from the holotype MCZ 1474, a three-dimensionally preserved partial skeleton including an incomplete skull and mandibles. The skull roof of Archeria is also articulated to the postcranial skeleton. It was collected in the Archer City Bonebed 1 site, from the Archer City Formation of the Wichita Group, dating to the Early Permian epoch. Apsisaurus was formerly assigned a

Pyozia is an extinct genus of basal Middle Permian varanopid synapsids known from Russia. It was first named by Jason S. Anderson and Robert R. Reisz in 2004 and the type species is Pyozia mesenensis. Pyozia mesenensis is known from the holotype PIN 3717/33, a three-dimensionally preserved partial skeleton including a nearly complete skull. It was collected from the Krasnoschelsk Formation, dating to the Capitanian stage of the Guadalupian epoch, about 264.28-263 million years ago.

Microvaranops is a Middle Permian synapsid of the family Varanopidae from the Abrahamskraal Formation of South Africa. It includes one species, Microvaranops parentis, which was probably arboreal. A slab containing five specimens of Microvaranops indicates that it gathered or lived in groups.

Thrausmosaurus is a genus of synapsid pelycosaurs from the extinct family Varanopidae. Like all that resemble members of Varanopidae, Thrausmosaurus most likely resembled the modern monitor lizard and may have had the same lifestyle. The type and only species was described by R. C. Fox in 1962, from three fossilized jaw fragments bearing teeth. The specimens were recovered from the fissure-fill deposits uncovered in a Limestone Quarry, north of Fort Sill, Comanche County, Oklahoma, USA. These deposits are dated to the Kungurian (Leonardian) of the Lower Permian.

Ruthiromia is an extinct genus of varanopid synapsids from the Early Permian of the United States.

Eoscansor (EE-oh-SKAN-sor; meaning "dawn climber") is a species of small varanopid amniote that lives from the upper Pennsylvanian subperiod in northern New Mexico, United States 305 million years ago. The species Eoscansor cobrensis was 24.5 centimeters (9.6 inches) long and weighed 58.3 grams. The tetrapods teeth indicated that it was insectivorous. The small size and grasping limbs means that was E. cobrensis highly agile and likely arboreal (tree climbing). The name Eoscansor means "dawn climber", derived from Greek "Eos" meaning dawn and Latin "scansor" meaning climber. E. cobrensis is cu

Dendromaia is an extinct genus of varanopid from the Carboniferous of Nova Scotia. It contains a single species, Dendromaia unamakiensis. Dendromaia is the oldest known varanopid and the only one found in Nova Scotia. Known from a large partial skeleton preserved with its tail wrapped around a much smaller partial skeleton, Dendromaia may also represent the oldest known occurrence of parental care in the fossil record. While the larger skeleton possessed certain mycterosaurine-like features, the smaller skeleton resembled basal varanopids such as Archaeovenator and Pyozia, creating uncertainty

Tambacarnifex (meaning "Tambach butcher") is an extinct genus of varanodontine synapsids known from the Early Permian Tambach Formation of Free State of Thuringia, central Germany. It was first named by David S. Berman, Amy C. Henrici, Stuart S. Sumida, Thomas Martens and Valerie Pelletier in 2013 and the type species is Tambacarnifex unguifalcatus.