Trematosauroidea Temporal range: Early Triassic - Middle Jurassic, | |
---|---|
Trematosaurus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | † Temnospondyli |
Suborder: | † Stereospondyli |
Clade: | † Trematosauria |
Superfamily: | † Trematosauroidea Watson, 1919 |
Families and genera | |
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.
A temnospondyl ilium was described in 2004 from the Callovian Toutunhe Formation in the Junggar Basin of China. Although the isolated bone was impossible to identify on the species level, it was referred to Trematosauroidea. The presence of this bone in the Toutunhe Formation extends the range of trematosauroids into the Middle Jurassic, making it one of only three groups of temnospondyls that survived the Triassic-Jurassic extinction event (the other two being the Brachyopoidea and possibly the Capitosauria). [1]
Below is a cladogram modified from Schoch (2011): [2]
Stereospondyli |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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.
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.
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).
Siderops is an extinct genus of chigutisaurid temnospondyl from Early Jurassic of Australia, containing the species S. kehli.
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.
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.
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.
Microposaurus is an extinct genus of trematosaurid temnospondyl. Fossils are known from the Cynognathus Assemblage Zone of the Beaufort Group in South Africa and the Rouse Hill Siltstone of Australia that date back to the Anisian stage of the Middle Triassic. These aquatic creatures were the short snouted lineage from Trematosaurinae.
Trematosauridae are a family of large marine temnospondyl amphibians with many members. They first appeared during the Induan age of the Early Triassic, and existed until around the Carnian stage of the Late Triassic, although by then they were very rare. By the Middle Triassic they had become widespread throughout Laurasia and Gondwana with fossils being found in Europe, Asia, Madagascar, and Australia. A possible trematosaurid has been found in the Toutunhe Formation in the Junggar Basin. If this analysis is accurate, it renders Trematosauridae one of the longest lived lineages of Temnospondyli, having lasted as recently as the late Jurassic.
The Mastodonsauroidea are an extinct superfamily of temnospondyl amphibians known from the Triassic. Fossils belonging to this superfamily have been found in North America, Greenland, Europe, Asia, and Australia. Ferganobatrachus from the Jurassic of Asia was initially assigned to this superfamily, but is now considered to be congeneric with the brachyopid Gobiops.
Calamops is an extinct genus of large temnospondyl amphibian known from the base of the Solebury Member of the Late Triassic Newark Supergroup of Pennsylvania, United States. Calamops was first named by Sinclair in 1917 and the type species is Calamops paludosus. It was usually thought to be a metoposaurid of questionable validity as its holotype and only known specimen, which comprises three pieces of a left mandibular ramus, had never been prepared. Following a preparation and casting of the specimen, Hans-Dieter Sues and Rainer R. Schoch found in 2013 Calamops to represent a valid taxon of trematosauroid temnospondyls that can be diagnosed by several autapomorphies. It represents one of the geologically youngest known long-snouted trematosaurs and the first record of these temnospondyls from the Late Triassic of North America. It is also the oldest known tetrapod fossil from the Triassic of the Newark basin.
Gobiops is an extinct genus of temnospondyl from the Jurassic of Mongolia, China, and possibly Kyrgyzstan. The genus is represented by a single species, Gobiops desertus. It was named in 1991 from the Late Jurassic Shar Teeg Beds of Mongolia. Additional material was described in 2005 from the Middle Jurassic Toutunhe Formation in the Junggar Basin of China. Gobiops belongs to the family Brachyopidae. The poorly known genus Ferganobatrachus, named in 1990 from Shar Teeg, is probably synonymous with Gobiops.
Luzocephalus is an extinct genus of temnospondyl amphibian from the Early Triassic of Russia. It is usually regarded as a member of the family Lydekkerinidae, although it has also been placed in the family Trematosauridae.
Rhineceps is an extinct genus of temnospondyl amphibian in the family Rhinesuchidae. Rhineceps was found in Northern Malawi in Southern Africa known only from its type species R. nyasaensis. Rhineceps was a late Permian semi-aquatic carnivore that lived in streams, rivers, lakes or lagoons. Rhineceps is an early divergent Stereopondyl within the family Rhinesuchidae, which only existed in the late Permian (Lopingian) and failed to survive the Permian-Triassic extinction unlike other stereospondyl families.
Plagiosuchus is an extinct genus of plagiosaurid temnospondyl. It is known from several collections from the Middle Triassic of Germany.
The Qigu Formation is a Late Jurassic (Oxfordian) geologic formation in the Southern Junggar Basin in China. Indeterminate Dinosaur remains are among the fossils that have been recovered from the formation, including theropod teeth and a fibula. a stegosaur dorsal vertebra and a Eusauropod tooth. Xinjiangtitan was erroneously thought to be from this formation, but it is actually from the older Qiketai Formation, which is in a different basin. The term "Qigu Formation" is also used to sediments of equivalent age in the Turpan Basin, but this might better be treated as a separate formation. It is laterally equivalent to the Shishugou Formation.
The Erfurt Formation, also known as the Lower Keuper, is a stratigraphic formation of the Keuper group and the Germanic Trias supergroup. It was deposited during the Ladinian stage of the Triassic period. It lies above the Upper Muschelkalk and below the Middle Keuper.
Manubrantlia was a genus of lapillopsid from the Early Triassic Panchet Formation of India. This genus is only known from a single holotype left jaw, given the designation ISI A 57. Despite the paucity of remains, the jaw is still identifiable as belonging to a relative of Lapillopsis. For example, all three of its coronoid bones possessed teeth, the articular bone is partially visible in lateral (outer) view, and its postsplenial does not contact the posterior meckelian foramen. However, the jaw also possesses certain unique features which justify the erection of a new genus separate from Lapillopsis. For example, the mandible is twice the size of any jaws referred to other lapillopsids. The most notable unique feature is an enlarged "pump-handle" shaped arcadian process at the back of the jaw. This structure is responsible for the generic name of this genus, as "Manubrantlia" translates from Latin to the English expression "pump-handle". The type and only known species of this genus is Manubrantlia khaki. The specific name refers to the greenish-brown mudstones of the Panchet Formation, with a color that had been described as "khaki" by the first British geologists who studied the formation.
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.