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.
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.
Metoposauroidea is an extinct superfamily of temnospondyls that lived from the Middle to Upper Triassic in North America, Europe and North Africa. Metoposauroidea includes the families Metoposauridae and Latiscopidae.
Sclerothorax is an extinct genus of temnospondyl from the Early Triassic of Germany. It is distinguished from other temnospondyls by its short and very wide skull and the elongated neural spines that form a ridge along its back. Sclerothorax is a basal member of Capitosauria, a large clade of temnospondyls that lived throughout the Triassic.
Chenoprosopus is a genus of extinct cochleosauridae that lived during late Carboniferous and early Permian periods. Two known species of Chenoprosopus are C. milleri and C. lewisi. Chenoprosopus lewisi was described in the basis of a virtually complete skull with maximum skull length of 95 mm. It is significantly smaller than Chenoprosopus milleri and was differentiated from that taxon by Hook (1993) based on sutural patterns of the skull roof. Hook also mentioned the reduced size of the vomerine tusks differentiated C. lewisi from C. milleri, but the different size of these tusks may be different ontogenetic stages of growth. Many of other cochleosaurids from the same time period have an elongated vomer and wide and elongate choana. However, Chenoprosopus is distinguished by its more narrowly pointed snout and separation between the nasal from the maxilla by the broad lacrimal-septomaxilla contact.
Apachesaurus is an extinct genus of metoposaurid temnospondyls from western North America.
Metoposauridae is an extinct family of trematosaurian temnospondyls. The family is known from the Triassic period. Most members are large, approximately 1.5 metres (4.9 ft) long and could reach 3 m long. Metoposaurids can be distinguished from the very similar mastodonsauroids by the position of their eyes, placed far forward on the snout.
Mastodonsauridae is a family of capitosauroid temnospondyls. Fossils belonging to this family have been found in North America, Greenland, Europe, Asia, and Australia. The family Capitosauridae is synonymous with Mastodonsauridae.
Eupelor is a dubious genus of prehistoric amphibian belonging to the temnospondyl family Metoposauridae. Fossils have been found in present-day Pennsylvania, within the Newark Supergroup, dating to the Late Triassic (Norian).
Arganasaurus is an extinct genus of temnospondyls belonging to the family Metoposauridae that lived in Morocco during the Late Triassic (Carnian).
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.
Dutuitosaurus is a genus of metoposaurids, a group of temnospondyls that lived during the Late Triassic period. Dutuitosaurus was discovered in the early 1960s in Morocco and is known from the lower t5 units of the Timezgadiouine Formation exposures in the Argana Basin of the High Atlas Mountains and was first described in 1976 by French paleontologist Jean-Michel Dutuit. Material of Dutuitosaurus is currently held in the Muséum national d'histoire naturelle (MNHN) in Paris, France. It was originally placed within Metoposaurus as M. ouazzoui but was subsequently placed in its own genus, Dutuitosaurus, by Hunt (1993), who identified a number of differences between Metoposaurus and the Moroccan metoposaurids. Features that differentiate Dutuitosaurus from other metoposaurids include relative elongate intercentra and a maxilla that enters the orbit.
Dictyocephalus is an extinct genus of prehistoric temnospondyls; the only species is Dictyocephalus elegans. This taxon was one of the first metoposaurids to be discovered in North America, being discovered by Ebeneezer Emmons and briefly described by Joseph Leidy in 1856 in the Newark supergroup exposures of Chatham County, North Carolina. At the time, Leidy was uncertain of much of the anatomy of D. elegans, which is represented only by a small partial skull and made only brief descriptions and measurements of a few elements, with an estimated size based on the long-snouted trematosaur Trematosaurus. Emmons provided the first figures of the specimen the following year. Romer (1947) briefly mentioned that the specimen was indistinguishable from "Buettneria" (Koskinonodon).
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.
Plagiosuchus is an extinct genus of plagiosaurid temnospondyl. It is known from several collections from the Middle Triassic of Germany.
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 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.
Polonosuchus is a genus of rauisuchid known from the late Triassic of Poland. It was a huge predator about 5–6 metres in length and, like all rauisuchians, was equipped with a large head of long sharp teeth. The legs were placed almost underneath the body, unlike most reptiles, which would have made it quite fast and a powerful runner. The appearance was very similar to that of the more known Postosuchus, of North America, and shared with the latter the ecological niche of the apex predator.
Callistomordax is an extinct genus of temnospondyl amphibian from the Middle Triassic of Germany. The type and only species, Callistomordax kugleri, was named in 2008. It is known from several well-preserved skeletons found in the Erfurt Formation, part of the Lower Keuper, which dates back to the late Ladinian stage.
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.
