Microsauria is an extinct, possibly polyphyletic order of tetrapods from the late Carboniferous and early Permian periods. It is the most diverse and species-rich group of lepospondyls. Recently, Microsauria has been considered paraphyletic, as several other non-microsaur lepospondyl groups such as Lysorophia seem to be nested in it. Microsauria is now commonly used as a collective term for the grade of lepospondyls that were originally classified as members of Microsauria.
Boii is an extinct genus of microsaur within the family Tuditanidae. It was found in Carboniferous coal from mines near the community of Kounov in the Czech Republic. The only remains of the genus consist of a crushed skull, shoulder girdle bones, and scales, which were similar to microsaurian elements originally referred to Asaphestera. Boii can be characterized by its heavily sculptured skull, thin ventral plate of the clavicles, and a larger number of fangs on the roof of the mouth. For many years the type and only known species, Boii crassidens, was considered to be a species of Sparodus, until 1966 when Robert Carroll assigned it to its own genus.
Batropetes is an extinct genus of brachystelechid recumbirostran "microsaur". Batropetes lived during the Sakmarian stage of the Early Permian. Fossils attributable to the type species B. fritschi have been collected from the town of Freital in Saxony, Germany, near the city of Dresden. Additional material has been found from the Saar-Nahe Basin in southwestern Germany and has been assigned to three additional species: B. niederkirchensis, B. palatinus, and B. appelensis.
Conjunctio is an extinct genus of dissorophid temnospondyl amphibian from the early Permian of New Mexico. The type species, Conjunctio multidens, was named by paleontologist Robert L. Carroll in 1964.
Carrolla is an extinct genus of brachystelechid 'microsaur' that lived in the Lower Permian in North America. It was named in 1986 by American paleontologists Wann Langston and Everett Olson. The type species, Carrolla craddocki, is the only known species.
Euryodus is an extinct genus of microsaur within the family Gymnarthridae. Euryodus is a Lepospondyl from the clade Microsauria that lived during the Lower Permian. The name comes from Greek, meaning ‘broad-tooth’. It has been found in the southern half of North America, from its original discovery in Texas up to Utah.
Hapsidopareion is an extinct genus of microsaur belonging to the family Hapsidopareiidae. Fossils have been found in the early Permian of Oklahoma.
Llistrofus is an extinct genus of early Permian microsaur within the family Hapsidopareiidae that is known from Oklahoma.
Ostodolepis is an extinct genus of microsaurian tetrapods within the family Ostodolepidae. It is known from the Arroyo Formation in Texas.
Rhynchonkos is an extinct genus of rhynchonkid microsaur. Originally known as Goniorhynchus, it was renamed in 1981 because the name had already been given to another genus; the family, likewise, was originally named Goniorhynchidae but renamed in 1988. The type and only known species is R. stovalli, found from the Early Permian Fairmont Shale in Cleveland County, Oklahoma. Rhynchonkos shares many similarities with Eocaecilia, an early caecilian from the Early Jurassic of Arizona. Similarities between Rhynchonkos and Eocaecilia have been taken as evidence that caecilians are descendants of microsaurs. However, such a relationship is no longer widely accepted.
Pariotichus is an extinct genus of gymnarthrid microsaurs from the early Permian of Texas.
Tersomius is an extinct genus of dissorophoid temnospondyl within the family Micropholidae. It is known from the early Permian of North America.
Hyloplesion is an extinct genus of microbrachomorph microsaur. It is the type and only genus within the family Hyloplesiontidae. Fossils have been found from the Czech Republic near the towns of Plzeň, Nýřany, and Třemošná, and date back to the Middle Pennsylvanian. The type species is H. longicostatum, named in 1883. Two species belonging to different genera, Seeleya pusilla and Orthocosta microscopica, have been synonymized with H. longicostatum and are thought to represent very immature individuals.
Brachystelechidae is an extinct family of Early Permian microsaurs. The family was first named by Robert L. Carroll and Pamela Gaskill in 1978, with the only member being Brachystelechus fritschi. Brachystelechus fritschi has since been reassigned to the genus Batropetes. Genera assigned to the family include: Batropetes, from Germany; Carrolla, from Texas; Quasicaecilia, also from Texas; Diabloroter, from the Mazon Creek lagerstätte of Illinois; and Bromerpeton from the Tambach Formation of Germany.
Gymnarthridae is an extinct family of the group Recumbirostra. Gymnarthrids are known from Europe and North America and existed from the Late Carboniferous through the Early Permian. Remains have been found from the Czech Republic, Nova Scotia, Illinois, Texas, and Oklahoma. Previously they were considered tuditanomorph microsaurs.
Ostodolepidae, also spelled Ostodolepididae, is an extinct family of Early Permian tetrapods. Initially they were considered microsaurs, but later were assigned to the group Recumbirostra. Ostodolepids were relatively large, reaching lengths of up to 2 feet (61 cm), terrestrial, and presumably fossorial. Ostodolepid remains have been found from Early Permian beds in Texas, Oklahoma, and Germany.
Tuditanidae is an extinct family of microsaurian tetrapods. Fossils have been found from Nova Scotia, Ohio, and the Czech Republic and are Late Carboniferous in age.
Parioxys is an extinct genus of temnospondyl amphibian from the Early Permian of Texas.
Huskerpeton is an extinct genus of recumbirostran from the Early Permian period. They belong to the order Microsauria, which was established in 1863 by Dawson, and was quickly expanded to include many different small taxa. They lived in what is now Nebraska and Kansas. The holotype of Huskerpeton was uncovered at the Eskridge formation in Nebraska, which is part of how it got its name.
Diabloroter is a Carboniferous genus of brachystelechid 'microsaur' from the Mazon Creek lagerstätte in Illinois. It was named in 2019 by Arjan Mann and Hillary C. Maddin.
