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.
Trematosauria is one of two major groups of temnospondyl amphibians that survived the Permian-Triassic extinction event, the other being the Capitosauria. The trematosaurs were a diverse and important group that included many medium-sized to large forms that were semi-aquatic to fully aquatic. The group included long-snouted forms such as the trematosauroids and short, broad-headed forms such as the metoposaurs. Although most groups did not survive beyond the Triassic, one lineage, the brachyopoids, continued until the Cretaceous period. Trematosauria is defined as all stereospondyls more closely related to Trematosaurus than to Parotosuchus, a capitosaurian.
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.
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.
Cyclotosaurus is an extinct genus of temnospondyl within the family Mastodonsauridae. It was of great size for an amphibian, had an elongated skull up to 56 cm (22 in).
Cherninia is an extinct genus of mastodonsaurid temnospondyl. The type species, Cherninia denwai, is known from the Denwa Formation of India. It is based on a massive skull, ISI A 54, which was originally considered a species of Parotosuchus in 1998 before being given its own genus in 2001.
Benthosuchus is an extinct genus of temnospondyl amphibian from the Early Triassic of Russia. It was primarily aquatic, living in rivers and lakes. Multiple species are known, with the largest reaching about 2.5 meters in length.
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.
Stereospondylomorpha is a clade of temnospondyls. It includes the superfamily Archegosauroidea and the more diverse group Stereospondyli. Stereospondylomorpha was first proposed by Yates and Warren (2000), who found Archegosauroidea and Stereospondyli to be sister taxa in their phylogenetic analysis. A similar clade is Archegosauriformes, named by Schoch and Milner (2000), which includes Stereospondyli and some Permian temnospondyls that are similar in appearance to stereospondyls, including the archegosauroids. However, according to Schoch and Milner's phylogeny, Archegosauroidea is a paraphyletic group of taxa that are successively basal to Stereospondyli, rather than a monophyletic sister taxon.
Limnarchia is a clade of temnospondyls. It includes the mostly Carboniferous-Permian age Dvinosauria and the mostly Permian-Triassic age Stereospondylomorpha. The clade was named in a 2000 phylogenetic analysis of stereospondyls and their relatives. Limnarchia means "lake rulers" in Greek, in reference to their aquatic lifestyles and long existence over a span of approximately 200 million years from the Late Carboniferous to the Early Cretaceous. In phylogenetic terms, Limnarchia is a stem-based taxon including all temnospondyls more closely related to Parotosuchus than to Eryops. It is the sister group of the clade Euskelia, which is all temnospondyls more closely related to Eryops than to Parotosuchus. Limnarchians represent an evolutionary radiation of temnospondyls into aquatic environments, while euskelians represent a radiation into terrestrial environments. While many euskelians were adapted to life on land with strong limbs and bony scutes, most limnarchians were better adapted for the water with poorly developed limbs and lateral line sensory systems in their skulls.
Almasaurus is an extinct genus of trematosaurian temnospondyl within the family Latiscopidae. It is known from several skulls and some postcranial material found from the Argana Formation in Morocco, which dates back to the Late Triassic.
Abiadisaurus is an extinct genus of prehistoric amphibians from the Temnospondyli clade, considered to be a member or a relative of the family Mastodonsauridae. It is known solely from the Late Triassic or Early Jurassic Adigrat Sandstone northwest of Abi Adi, Tigray, Ethiopia. The Age debate of this taxon comes in part due to the fact the Adigrat Sandstone is believed to be diachronous, with a top age of Callovian(?) to early Oxfordian marine Antalo Limestone and the Hamanlei Formation, but some beds overlie Paleozoic formations. These sandstones were deposited on top of the partially eroded Triassic surface, primarily in fluvial or piedmont environments, but also in fluviolacustrine and deltaic settings.
Bukobaja is an extinct genus of mastodonsaurid temnospondyl from the middle Triassic of Russia. It contains a single species, Bukobaja enigmatica. Bukobaja mainly occurs in the Bukobay Svita as part of the Ladinian?-age "Mastodonsaurus fauna", a section of Russian Triassic biostratigraphy characterized by "Mastodonsaurus" torvus. It was also present in the underlying Donguz Svita. Bukobaja appears to be a valid genus similar to, yet distinct from, Mastodonsaurus. Despite appearing to possess several unique features, Bukobaja is still known from very few remains. This has led to difficulties in determining its relations more precisely than "Mastodonsauridae incertae sedis". It has also been compared to trematosaurids.
Bulgosuchus is an extinct genus of prehistoric amphibians, known from an incomplete mandible and a femur recovered from the Bulgo Sandstone at Long Reef in Sydney, Australia. The type species is Bulgosuchus gargantua, which was named in 1999.
Lapillopsis is an extinct genus of stereospondyl temnospondyl within the family Lapillopsidae. Fossils belonging to the genus have been found in the Arcadia Formation of Queensland, Australia.
Odenwaldia is an extinct genus of mastodonsauroid temnospondyl within the family Heylerosauridae.
Wellesaurus is an extinct genus of mastodonsauroid temnospondyl. They were amphibious carnivores that lived in freshwater environments.
Stenotosaurus is an extinct genus of capitosaurian temnospondyl within the family Stenotosauridae. It is known from three species, all of which lived during the Anisian stage of the Middle Triassic. Fossils have been found in England and Germany.
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.
Tatrasuchus is an extinct genus of temnospondyl from the Middle Triassic of Poland and Germany. It is classified as a member of the family Cyclotosauridae or Mastodonsauridae. It is closely related to the genus Cyclotosaurus. The type species, Tatrasuchus kulczyckii, was named in 1996. Damiani (2001) considered genus Kupferzellia Schoch (1997) from the Middle Triassic of Germany to be a junior synonym of Tatrasuchus, and recombined its type species, K. wildi as the second species of Tatrasuchus. This classification was followed by some authors, e.g. Fortuny et al. (2011); other authors, e.g. Schoch (2008), maintain Tatrasuchus and Kupferzellia as distinct genera. However, Schoch & Moreno (2024) synonymized the two genera, maintaining T. wildi as a distinct species from T. kulczyckii.
