Temnospondyli or temnospondyls is a diverse ancient order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian and Triassic periods, with fossils being found on every continent. A few species continued into the Jurassic and Early Cretaceous periods, but all had gone extinct by the Late Cretaceous. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are amphibians, many had characteristics such as scales and large armour-like bony plates (osteoderms) that generally distinguish them from the modern soft-bodied lissamphibians.
Koolasuchus is an extinct genus of brachyopoid temnospondyl in the family Chigutisauridae. Fossils have been found from Victoria, Australia and date back 125-120 million years ago to Barremian-Aptian stages of the Early Cretaceous. Koolasuchus is the youngest known temnospondyl. It is known from several fragments of the skull and other bones such as vertebrae, ribs, and pectoral elements. The type species Koolasuchus cleelandi was named in 1997. K. cleelandi was adopted as the fossil emblem for the state of Victoria, Australia on 13 January 2022.
Dvinosaurs are one of several new clades of temnospondyls named in the phylogenetic review of the group by Yates and Warren 2000. They represent a group of primitive semi-aquatic to completely aquatic temnospondyls, and are known from the Late Carboniferous to the Early Triassic, being most common in the Permian period. Their distinguishing characteristics are a reduction of the otic notch; the loss of a flange on the rear side of the pterygoid; and 28 or more presacral vertebrae.
The Stereospondyli are a group of extinct temnospondyl amphibians that existed primarily during the Mesozoic period. They are known from all seven continents and were common components of many Triassic ecosystems, likely filling a similar ecological niche to modern crocodilians prior to the diversification of pseudosuchian archosaurs.
Pleurodont is a form of tooth implantation common in reptiles of the order Squamata, as well as in at least one temnospondyl. The vestibular (outer) side of pleurodont teeth are fused (ankylosed) to the inner surface of the jaw bones which host them. The lingual (tongue) side of pleurodont teeth are not attached to bone, and instead are typically held in place by connective ligaments. This contrasts with thecodont implantation, in which the teeth are set in sockets and surrounded by bone on all sides.
Eryosuchus is an extinct genus of capitosauroid temnospondyl from the Middle Triassic of northern Russia. It was a very large predator: the largest specimen known could reach up to 3.5 m (11.5 ft) in length, with a skull over 1 m long.
Chigutisauridae is an extinct family of large temnospondyls. The only genera recognized as belonging to Chigutisauridae at the current time are all from Gondwana. Chigutisaurids first appeared during the Early Triassic in Australia. During the Late Triassic they became widely distributed in Gondwana, with fossils found in South Africa, India and South America. Koolasuchus from the Early Cretaceous of Australia represents the youngest known temnospondyl.
Pelorocephalus is an extinct genus of chigutisaurid temnospondyls. It is known from the Late Triassic (Carnian) Cacheutá Formation of the Cuyo Basin and the Ischigualasto Formation of the Ischigualasto-Villa Unión Basin, both in northwestern Argentina. Four species are currently recognized: the type species P. mendozensis, which was named in 1944, P. tenax, which was named in 1949 as a species of Chigutisaurus and reassigned to Pelorocephalus in 1999, and P. cacheutensis, which was named in 1953 as another species of Chigutisaurus and reassigned to Pelorocephalus along with P. tenax. A fourth species, P. ischigualastensis, was named in 1975 after the formation it was found in. The species P. tunuyanensis was named in 1948 but has since been synonymized with P. mendozensis.
Siderops is an extinct genus of chigutisaurid temnospondyl from Early Jurassic of Australia, containing the species S. kehli.
Brachyopidae is an extinct family of temnospondyls. They evolved in the early Mesozoic and were mostly aquatic. A fragmentary find from Lesotho, Africa is estimated to have been 7 metres (23 ft) long, the largest amphibian ever known to have lived besides Prionosuchus and Mastodonsaurus. Brachyopids were the only group of temnospondyls to survive into the Jurassic aside from their sister family Chigutisauridae; there are records of brachyopids from the Jurassic of Asia.
Lydekkerinidae is a family of stereospondyl temnospondyls that lived in the Early Triassic period. During this time period, lydekkerinids were widely distributed, with putative remains reported from Russia, Greenland, India, South Africa, Madagascar, Australia, and Antarctica. In contrast to most other stereospondyls, lydekkerinids were relatively small-bodied. The type genus is Lydekkerina, the namesake of the family and the best-known lydekkerinid.
Trematosauridae is a family of large marine temnospondyls with several included genera.
Acroplous is an extinct genus of dvinosaurian Temnospondyli within the family Eobrachyopidae.
Bothriceps is an extinct genus of stereospondyl temnospondyl. It is a member of the infraorder Trematosauria and is the most basal brachyopomorph known. It may be the only brachyopomorph that lies outside the superfamily Brachyopoidea, which includes the families Brachyopidae and Chigutisauridae. It shares several similarities to Keratobrachyops, another basal brachyopomorph, and may be closely related to or even synonymous with it.
Gobiops is an extinct genus of temnospondyl from the Jurassic of Mongolia, China, and possibly Kyrgyzstan. The genus is represented by a single species, Gobiops desertus. It was named in 1991 from the Late Jurassic Shar Teeg Beds of Mongolia. Additional material was described in 2005 from the Middle Jurassic Toutunhe Formation in the Junggar Basin of China. Gobiops belongs to the family Brachyopidae. The poorly known genus Ferganobatrachus, named in 1990 from Shar Teeg, is probably synonymous with Gobiops.
Keratobrachyops is an extinct genus of trematosaurian temnospondyl found in the Arcadia Formation of Queensland, Australia. It had been thought to be a basal chigutisaurid but is now thought to be a basal brachyopomorph closely related to the genus Bothriceps, and may even be a synonym of it.
Kourerpeton is an extinct genus of dvinosaurian temnospondyl. Fossils of Kourerpeton were discovered in a window of a barber's shop in either Bisbee or Mesa, Arizona. Kourerpeton was named in 1976, with the type and only species being K. bradyi. It was originally assigned to the monotypic family Kourerpetidae, which has been alternatively spelled Kourerpetontidae.
Brachyopomorpha is a clade of stereospondyl temnospondyls within the infraorder Trematosauria. It was constructed in 2000 to include Bothriceps australis and the superfamily Brachyopoidea. It is phylogenetically defined as a stem-based taxon including Pelorocephalus and all taxa closer to it than to Rhytidosteus. In contrast, Brachyopoidea is defined as a node-based taxon including Brachyops and Pelorocephalus and all descendants of their most recent common ancestor. Because Bothriceps is not thought to be a descendant of that recent common ancestor and would be more basal than it, the genus is placed just outside Brachyopoidea and is considered to be a sister taxon to the clade.
Rhytidostea is a clade of stereospondyl temnospondyls. It was erected in 2000 to include several temnospondyl groups distinct from the "higher" group of capitosaurs, including lydekkerinids, brachyopoids, and rhytidosteids. Rhytidosteans first appeared in the Permian period and underwent an evolutionary radiation during the Induan stage of the Early Triassic. Along with capitosaurs, rhytidosteans comprise much of the larger suborder Stereospondyli. Rhytidostea has often been considered the sister group of the clade Capitosauria, but has been placed in various other phylogenetic positions. In many studies, members of Rhytidostea are split, with lydekkerinids having a more basal position among stereospondyls while rhytidosteids and brachyopoids form a group placed among the more derived trematosaurian stereospondyls.
Vigilius is an extinct genus of brachyopid temnospondyl amphibian from the Triassic of Arizona. It is known from the single type species Vigilius wellesi.
