An anapsid is an amniote whose skull lacks one or more skull openings near the temples. Traditionally, the Anapsida are the most primitive subclass of amniotes, the ancestral stock from which Synapsida and Diapsida evolved, making anapsids paraphyletic. It is however doubtful that all anapsids lack temporal fenestra as a primitive trait, and that all the groups traditionally seen as anapsids truly lacked fenestra.
Pareiasaurs are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with scutes which covered large areas of the body. They first appeared in southern Pangea during the Middle Permian, before becoming globally distributed during the Late Permian. Pareiasaurs were the largest reptiles of the Permian, reaching sizes equivalent to those of contemporary therapsids. Pareiasaurs became extinct at the end of the Permian during the Permian-Triassic extinction event.
Parareptilia is a subclass or clade of basal sauropsids (reptiles), typically considered the sister taxon to Eureptilia. Parareptiles first arose near the end of the Carboniferous period and achieved their highest diversity during the Permian period. Several ecological innovations were first accomplished by parareptiles among reptiles. These include the first reptiles to return to marine ecosystems (mesosaurs), the first bipedal reptiles, the first reptiles with advanced hearing systems, and the first large herbivorous reptiles. The only parareptiles to survive into the Triassic period were the procolophonoids, a group of small generalists, omnivores, and herbivores. The largest family of procolophonoids, the procolophonids, rediversified in the Triassic, but subsequently declined and became extinct by the end of the period.
The Procolophonia are a suborder of herbivorous reptiles that lived from the Middle Permian till the end of the Triassic period. They were originally included as a suborder of the Cotylosauria but are now considered a clade of Parareptilia. They are closely related to other generally lizard-like Permian reptiles such as the Millerettidae, Bolosauridae, Acleistorhinidae, and Lanthanosuchidae, all of which are included under the Anapsida or "Parareptiles".
Claudiosaurus is an extinct genus of diapsid reptiles from the Permian Sakamena Formation of the Morondava Basin, Madagascar. The pattern of the vertebrate, girle, and limbs indicates that Claudiosaurus and Thadeosaurus share a common ancestor.
Hovasaurus is an extinct genus of diapsid reptile belonging to the order Eosuchia. It lived in what is now Madagascar during the Late Permian and Early Triassic, being a survivor of the Permian–Triassic extinction event and the paleontologically youngest member of the Tangasauridae. Fossils have been found in the Permian Lower and Triassic Middle Sakamena Formations of the Sakamena Group, where it is amongst the commonest fossils. Its morphology suggests an aquatic ecology.
Procolophonidae is an extinct family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, South America, Antarctica and Australia. The most primitive procolophonids were likely insectiovous or omnivorous, more derived members of the clade developed bicusped molars, and were likely herbivorous feeding on high fiber vegetation or durophagous omnivores. Many members of the group are noted for spines projecting from the quadratojugal bone of the skull, which likely served a defensive purpose as well as possibly also for display. At least some taxa were likely fossorial burrowers. While diverse during the Early and Middle Triassic, they had very low diversity during the Late Triassic, and were extinct by the beginning of the Jurassic.
Procolophon is a genus of lizard-like procolophonid parareptiles that first appeared in the Early Triassic (Induan) of South Africa, Brazil, and Antarctica. It persisted through the Permian–Triassic extinction event, but went extinct in the beginning of the Early Middle Triassic. The type species is P. trigoniceps.
Nycteroleter is an extinct genus of nycteroleterid parareptile known from the Middle Permian of European Russia. Fossils were first found in the Mezen River, near to Arkhangelsk. Within the Nycteroleteridae, it is considered most closely related to Emeroleter. However, its legs were shorter than those of Emeroleter and its skull was flatter. Nycteroleter was insectivorous, and may have been nocturnal. It was a small animal, less than a metre long.
Acleistorhinus (ah-kles-toe-RYE-nuss) is an extinct genus of parareptile known from the Early Permian of Oklahoma. It is notable for being the earliest known anapsid reptile yet discovered. The morphology of the lower temporal fenestra of the skull of Acleistorhinus bears a superficial resemblance to that seen in early synapsids, a result of convergent evolution. Only a single species, A. pteroticus, is known, and it is classified in the Family Acleistorhinidae, along with Colobomycter.
Microleter is an extinct genus of basal procolophonomorph parareptiles which lived in Oklahoma during the Early Permian period. The type and only known species is Microleter mckinzieorum. Microleter is one of several parareptile taxa described from the Richards Spur fissure fills, and can be characterized from its high tooth count, lacrimal/narial contact, short postfrontal, and slit-like temporal emargination edged by the postorbital, jugal, squamosal, and quadratojugal. Contrary to Australothyris, which had a similar phylogenetic position as a basal procolophonomorph, Microleter suggests that early parareptile evolution occurred in Laurasia and that multiple lineages developed openings or emarginations in the temporal region.
Variodens is an extinct genus of trilophosaur. Fossils have been found from the Emborough Quarries in the Mendip Hills of Somerset, England. These fossils have been uncovered from a Late Triassic fissure fill within Carboniferous-age limestone. The type and only known species is V. inopinatus, named in 1957.
Phaanthosaurus is an extinct genus of basal procolophonid parareptile from early Triassic deposits of Nizhnii Novgorod, Russian Federation. It is known from the holotype PIN 1025/1, a mandible. It was collected from Vetluga River, Spasskoe village and referred to the Vokhmian terrestrial horizon of the Vokhma Formation. It was first named by P. K. Chudinov and B. P. Vjushkov in 1956 and the type species is Phaanthosaurus ignatjevi.
Nyctiphruretidae is an extinct family of hallucicranian parareptiles known from the late Early to the late Middle Permian of European Russia and south-central United States.
Anomoiodon is an extinct genus of procolophonine procolophonid parareptile from early Triassic deposits of Thuringia, Germany. It is known only from the holotype MB.R.3539B and paratype MB.R.3539A, two articulated, three-dimensionally preserved partial skeletons on one block which represent two individuals. The holotype includes nearly complete skull and lower jaw. The block was collected from the lowest layer of the Chirotherium Sandstone Member of the Solling Formation, dating to the early Olenekian faunal stage of the Early Triassic, about 249-247 million years ago. It was first named by Friedrich von Huene in 1939 and the type species is Anomoiodon liliensterni. Laura K. Säilä, who redescribed Anomoiodon in 2008, found it to be a leptopleuronine using a phylogenetic analysis. The most recent analysis, performed by Ruta et al. (2011) found it to be a procolophonine instead. However, both analyses found that it is most closely related to the Russian procolophonid Kapes.
Kapes is an extinct genus of procolophonid parareptile from the Lower and Middle Triassic of the United Kingdom and Russia. It is a member of the subfamily Procolophoninae. The type species K. amaenus was named in 1975 from the banks of the Vychegda River in the Komi Republic of Russia. In 1983, a new species was brought into the genus, K. majmesculae. K. majmesculae was first named in 1968 as a member of the genus Tichvinskia. A third Russian species, K. serotinus, was named in 1991. In 2002, Kapes bentoni was named from the Middle Triassic Otter Sandstone Formation of Devon, England, extending the geographic range of Kapes. In the same paper, K. serotinus was synonymized with K. majmesculae and another Russian species was assigned to Kapes called K. komiensis. K. komiensis was first named in 1975 as a member of the genus Macrophon.
Coelodontognathus is an extinct genus of reptile from the Early Triassic of European Russia. It was originally described as a procolophonid parareptile in 1967 but was reclassified as a possible trilophosaurid archosauromorph in 2008. The genus includes two species: the type species C. donensis and C. ricovi. C. donensis is known from the holotype PIN 4173/129 and the referred PIN 4173/130, and C. ricovi is known from the holotype PIN 4173/127 and the referred PIN 4173/128, all of which represent dentaries that are housed at the Paleontological Institute, Russian Academy of Sciences. Another dentary, SGU 104/3105, originally referred to C. donensis was reassigned to its own genus and species Vitalia grata by Ivakhnenko, 1973. The fossils have been found at the Donskaya Luka Locality near the village of Sirotinskaya and the Don River in Ilovlinsky District, Volgograd Oblast, from the Lipovskaya Formation of the Gamskii Horizon. Like Coelodontognathus, Vitalia which is known from the same locality was also first identified as a procolophonid and later reclassified as a trilophosaurid. Coelodontognathus and Vitalia are similar to procolophonids in that they have wide teeth but differs from them in that they have tooth roots set deep into the jaws.
Barasaurus is an extinct genus of owenettid procolophonoid parareptile known from the late Late Permian and early Early Triassic of Madagascar. It contains a single species, Barasaurus besairiei.
Vitalia is an extinct genus of reptile from the Early Triassic of European Russia known from the type species V. grata. It is known from the holotype dentary PIN 4173/126 as well as two additional dentaries PIN 1043/627 and 1043/628, all housed at the Paleontological Institute, Russian Academy of Sciences. The type dentary was originally included in the hypodigm of Coelodontognathus donensis named by the notable Russian vertebrate paleontologist Vitaliy Georgiyevich Ochev in 1967. Ivakhnenko (1973) separated the specimen and gave it its own genus and species name in light of the new material, which he named in honor of Ochev. The dentaries of Vitalia were collected at the Donskaya Luka Locality near the village of Sirotinskaya in Ilovlinsky District, Volgograd Oblast, from the Lipovskaya Formation of the Gamskii Horizon. Like Coelodontognathus, Vitalia was originally described as a procolophonid parareptile in 1973, but Arkhangelskii & Sennikov (2008) reclassified the taxon as a possible trilophosaurid archosauromorph. Vitalia is thought to be similar to the possible trilophosaurids Coelodontognathus and Doniceps, both of which are known exclusively from the same locality. Coelodontognathus and Vitalia are similar to procolophonids in that they have wide teeth but differs from them in that they have tooth roots set deep into the jaws.
Eomurruna is a genus of procolophonid reptile that existed in what is now Queensland, Australia during the Early Triassic period. The genus is made up of a single species, E. yurrgensis, originally uncovered within the Arcadia Formation in 1985. Since then over 40 specimens have been referred to the genus, making Eomurruna one of the most complete organisms so far found from the Mesozoic of Australia.
