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 armour-like bony plates that 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.
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.
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.
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.
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.
Hadrokkosaurus is an extinct genus of brachyopid temnospondyl amphibian from the Middle Triassic of the southwestern United States. It includes a single species, Hadrokkosaurus bradyi, known from the Moenkopi Formation of Arizona.
Cosgriffius is an extinct genus of trematosaurian temnospondyl within the family Trematosauridae. It was described in 1993 by Samuel P. Welles based on a single partial skull from the well-known Meteor Crater Quarry in Arizona that also produced more abundant remains of the capitosaur Wellesaurus peabodyi. The skull was long and slender, features typically associated with the trematosaurid subfamily Lonchorhynchinae. This is the only trematosaurid known from western North America.
Luzocephalus is an extinct genus of temnospondyl amphibian from the Early Triassic of Russia and Greenland. It is usually regarded as a member of the family Lydekkerinidae, although it has also been placed in the family Trematosauridae.
Rotaurisaurus is an extinct genus of amphibian-grade tetrapod from the family Lapillopsidae. This genus is known only from an incomplete crushed skull and associated left jaw, together given the designation UTGD 87795. The generic name, Rotaurisaurus, is a combination of Latin words translating to "circle-eared lizard". This references the shape of its otic notches, which acquire a circular form due to being partially enclosed by the tabular bones at the back of the skull. The specific name, contundo, references the specimen's poor level of preservation, as it is derived from the Latin word for "squashed".
Rileymillerus is an extinct genus of temnospondyl amphibian from the Late Triassic Post Quarry in the Dockum Group of Texas that was described by John Bolt and Sankar Chatterjee in 2000. The holotype, a nearly complete skull with articulated jaws, is housed at the Museum of Texas Tech University. The genus is named for Riley Miller, who allowed Chatterjee to work on the Post Quarry, and the species is named for the paleontologist John Cosgriff.
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.
Plagiobatrachus is an extinct genus of plagiosaurid temnospondyl. It is known from the Rewan Formation, an Early Triassic formation in Australia.
Thoosuchus is an extinct genus of basal trematosauroid trematosaurian temnospondyl. Fossils have been found from Russia and date back to the Early Triassic. It is the type genus of the family Thoosuchidae, formerly called the subfamily Thoosuchinae and placed within Benthosuchidae. The benthosuchids were originally composed of the majority of basal trematosaurian forms regarded as the ancestors of the trematosaurids. Although the genus was first named in 1940, material from one species, E. yakovlevi, was originally tentatively referred to Trematosuchus in 1926.
Warrenisuchus is an extinct genus of temnospondyl amphibian from the Early Triassic of Queensland, Australia. It belongs to a diverse group of Triassic temnospondyls called Capitosauria. The type species Warrenisuchus aliciae was erected in 2009. W. aliciae was originally described as a species of Parotosuchus in 1988, which is known from other species that have been found in Europe, Africa, and Antarctica. In 2000 it was then assigned to a new genus called Rewanobatrachus along with the newly named species R. gunganj, which was declared the type species of the genus. However, R. gunganj was later reclassified as a species of Watsonisuchus, invalidating the name Rewanobatrachus and requiring that R. aliciae be placed in its own genus, which was named Warrenisuchus. However, several studies suggest that Warrenisuchus aliciae may be a species of Watsonisuchus as well. Unlike most capitosaurs, Warrenisuchus is known from many juvenile skulls less than 4 centimetres (1.6 in) in length.
Panthasaurus is an extinct genus of large temnospondyl amphibian 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.
Latiscopus disjunctus is a small Late Triassic temnospondyl collected in 1940 by a Works Projects Administration crew working near Otis Chalk, Texas that was described by John Wilson in 1948.
