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.
Trematosauroidea are an important group of Triassic temnospondyl amphibians. They flourished briefly during the Early Triassic, occurring worldwide before declining at the start of the Middle Triassic, although the group continued until the Late Triassic. They were medium-sized temnospondyls with wedge-shaped tails, narrow skulls, and, in advanced forms, elongated snouts. The latter feature was probably an adaptation for feeding on fish. The largest and most specialized family, the Trematosauridae, are the only batrachomorphs to have adapted to a marine lifestyle with the exception of the modern crab-eating frog.
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.
Siderops is an extinct genus of chigutisaurid temnospondyl from Early Jurassic of Australia, containing the species S. kehli.
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.
Deltasaurus is an extinct genus of Carnian temnospondyl amphibian of the family Rhytidosteidae.
Brachyopoidea is a superfamily of temnospondyls that lived during the Mesozoic. It contains the families Brachyopidae and Chigutisauridae. The earliest records of brachyopids are from the Lower Triassic in Australia. The latest-surviving member of the superfamily is the chigutisaurid Koolasuchus from the Early Cretaceous of Australia.
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.
Trematosauridae is a family of large marine temnospondyls with several included genera.
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.
Rhytidosteoidea is a superfamily of Temnospondyli, early amphibian species that existed during the Carboniferous, Permian, and Triassic periods. The taxon was established in 1965 to accommodate two new species of Deltasaurus, the author recognising an alliance with previously described genera.
Austropelor is an extinct genus of possible chigutisaurid temnospondyl from the Early Jurassic of Australia. Fossil remains were found in the Marburg Sandstone Formation.
Arcadia is an extinct genus of temnospondyl amphibians in the family Rhytidosteidae from the early Triassic. The remains were found in and named after the Arcadia Formation of Australia.
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.
Derwentia is an extinct genus of trematosaurian temnospondyl within the family Rhytidosteidae. It is known from a single skull found from the Knocklofty Sandstone of Tasmania, which is Early Triassic in age.
Xenotosuchus is an extinct genus of mastodonsaurid temnospondyl within the family Mastodonsauridae known from the Triassic of South Africa. The genus is based on a skull originally described as Parotosuchus, an animal which it resembled in general build and habit.
Yarengia is an extinct genus of temnospondyl amphibian in the superfamily Mastodonsauroidea. It is known from Yarenga River, representing the Triassic of Russia.
Anaschisma is an extinct genus of large temnospondyls. These animals were part of the family called Metoposauridae, which filled the crocodile-like predatory niches in the late Triassic. It had a large skull about 62 centimetres (24 in) long, and possibly reached 3 metres (9.8 ft) long. It was an ambush hunter, snapping up anything small enough to fit in its huge jaws. It was very common during the Late Triassic in what is now the American Southwest.
The Salientia are a total group of amphibians that includes the order Anura, the frogs and toads, and various extinct proto-frogs that are more closely related to the frogs than they are to the Urodela, the salamanders and newts. The oldest fossil "proto-frog" appeared in the early Triassic of Madagascar, but molecular clock dating suggests their origins may extend further back to the Permian, 265 million years ago.
Panthasaurus is an extinct genus of large temnospondyl belonging to the family Metoposauridae that lived in India during the Late Triassic (Norian) of central India. It contains one species, Panthasaurus maleriensis from the Lower Maleri Formation of India.
