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.
Seymouria is an extinct genus of seymouriamorph from the Early Permian of North America and Europe. Although they were amphibians, Seymouria were well-adapted to life on land, with many reptilian features—so many, in fact, that Seymouria was first thought to be a primitive reptile. It is primarily known from two species, Seymouria baylorensis and Seymouria sanjuanensis. The type species, S. baylorensis, is more robust and specialized, though its fossils have only been found in Texas. On the other hand, Seymouria sanjuanensis is more abundant and widespread. This smaller species is known from multiple well-preserved fossils, including a block of six skeletons found in the Cutler Formation of New Mexico, and a pair of fully grown skeletons from the Tambach Formation of Germany, which were fossilized lying next to each other.
Paracyclotosaurus is an extinct genus of temnospondyl, which would have appeared similar to today's salamander – but much larger, measuring up to 2.45 m (8.0 ft) long and weighing between 159 and 365 kg. It lived in the Middle Triassic period, about 235 million years ago, and fossils have been found in Australia, India, and South Africa.
Mastodonsaurus is an extinct genus of temnospondyl from the Middle Triassic of Europe. It belongs to a Triassic group of temnospondyls called Capitosauria, characterized by their large body size and presumably aquatic lifestyles. Mastodonsaurus remains one of the largest amphibians known, and may have exceeded 6 meters in length.
Metoposaurus meaning "front lizard" is an extinct genus of stereospondyl temnospondyl amphibian, known from the Late Triassic of Germany, Italy, Poland, and Portugal. This mostly aquatic animal possessed small, weak limbs, sharp teeth, and a large, flat head. This highly flattened creature mainly fed on fish, which it captured with its wide jaws lined with needle-like teeth. Many Metoposaurus mass graves have been found, probably from creatures that grouped together in drying pools during drought.
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).
Dasyceps is an extinct genus of zatracheidid temnospondyl from the early Permian of England.
Eocyclotosaurus is an extinct genus of mastodonsauroid temnospondyl from the Middle Triassic (Anisian). The name Eocyclotosaurus means "dawn round-eared lizard". It is characterized as a capitosauroid with a long and slender snout, closed otic fenestra, and small orbits. It measured over one metre and had a 22 cm skull.
Rhinesuchidae is a family of tetrapods that lived primarily in the Permian period. They belonged to the broad group Temnospondyli, a successful and diverse collection of semiaquatic tetrapods which modern amphibians are probably descended from. Rhinesuchids can be differentiated from other temnospondyls by details of their skulls, most notably the interior structure of their otic notches at the back of the skull. They were among the earliest-diverging members of the Stereospondyli, a subgroup of temnospondyls with flat heads and aquatic habits. Although more advanced stereospondyls evolved to reach worldwide distribution in the Triassic period, rhinesuchids primarily lived in the high-latitude environments of Gondwana during the Guadalupian and Lopingian epochs of the Permian. The taxonomy of this family has been convoluted, with more than twenty species having been named in the past; a 2017 review recognized only eight of them to be valid. While several purported members of this group have been reported to have lived in the Triassic period, most are either dubious or do not belong to the group. However, at least one valid genus of rhinesuchid is known from the early Triassic, a small member known as Broomistega. The most recent formal definition of Rhinesuchidae, advocated by Mariscano et al. (2017) is that of a stem-based clade containing all taxa more closely related to Rhinesuchus whaitsi than to Lydekkerina huxleyi or Peltobatrachus pustulatus. A similar alternate definition is that Rhinesuchidae is a stem-based clade containing all taxa more closely related to Uranocentrodon senekalensis than to Lydekkerina huxleyi, Trematosaurus brauni, or Mastodonsaurus giganteus.
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.
Cryobatrachus is an extinct genus of temnospondyl amphibian from the Early Triassic of Antarctica. The type species is Cryobatrachus kitchingi. It is known from a partial skull and an imprint of the skull roof, both found in the Fremouw Formation of the Transantarctic Mountains at about 85° south latitude and described in 1974. Many small bone fragments have also been identified, although they cannot be attributed with certainty to C. kitchingi. Cryobatrachus has been classified in the family Lydekkerinidae, as it is similar in appearance to the genus Lydekkerina from South Africa. Because only a small number of features distinguish it from other lydekkerinids, Cryobatrachus kitchingi has more recently been considered a nomen dubium, meaning that its distinction from other better-known species may be unwarranted.
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.
Rotaurisaurus is an extinct genus of temnospondyls 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".
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.
Stanocephalosaurus is an extinct genus of large-sized temnospondyls living through the early to mid Triassic. The etymology of its name most likely came from its long narrow skull when compared to other temnospondyls. Stanocephalosaurus lived an aquatic lifestyle, with some species even living in salt lakes. There are currently three recognized species and another that needs further material to establish its legitimacy. The three known species are Stanocephalosaurus pronus from the Middle Triassic in Tanzania, Stanocephalosaurus amenasensis from the Lower Triassic in Algeria, and Stanocephalosaurus birdi, from the middle Triassic in Arizona. Stanocephalosaurus rajareddyi from the Middle Triassic in central India needs further evidence in order to establish its relationship among other Stanocephalosaurs. Like other temnospondyls, Stanocephalosaurus was an aquatic carnivore. Evidence of multiple species discovered in a wide range of localities proves that Stanocephalosaurus were present all across Pangea throughout the early to mid Triassic.
Subcyclotosaurus is an extinct genus of carnivorous mastodonsaurid temnospondyl. It is known from a single partial skull from the Hawkesbury Sandstone formation in Australia.
Micropholis is an extinct genus of dissorophoid temnospondyl. Fossils have been found from the Lystrosaurus Assemblage Zone of the Karoo Basin in South Africa and are dated to the Induan. Fossils have also been found from the lower Fremouw of Antarctica.Micropholis is the only post-Permian dissorophoid and the only dissorophoid in what is presently the southern hemisphere and what would have been termed Gondwana during the amalgamation of Pangea.
Arachana is an extinct genus of rhinesuchid-like temnospondyl known from the Early Triassic Buena Vista Formation of northeastern Uruguay. Arachana was first named by Graciela Piñeiro, Alejandro Ramos and Claudia Marsicano in 2012 and the type species is A. nigra. It shares characteristics with both rhinesuchids and lydekkerinids, making it a transitional form between basal and more advanced stereospondyls.
Warrenisuchus is an extinct genus of temnospondyl 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.
