Silphedosuchus Temporal range: Early Triassic | |
---|---|
Life restoration of Silphedosuchus orenburgensis | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Therapsida |
Suborder: | † Therocephalia |
Family: | † Ericiolacertidae |
Genus: | † Silphedosuchus Tatarinov, 1977 |
Type species | |
†Silphedosuchus orenburgensis Tatarinov, 1977 |
Silphedosuchus is an extinct genus of therocephalian therapsids from the Early Triassic of Russia. It is a member of the family Ericiolacertidae, along with the genus Ericiolacerta from South Africa and Antarctica. The type species Silphedosuchus orenburgensis was described in 1977 on the basis of a single holotype skull from Orenburg Oblast. [1]
Silphedosuchus was found in the Rassypnaya locality of Orenburg Oblast, dating back to the Olenekian stage of the Early Triassic. It was found in a fine-grained sandstone that contains few other vertebrates. This layer was deposited in a large floodplain that covered much of European Russia during the Early Triassic. At the Rassypnaya locality, a lens of coarser sand, presumably deposited by an ancient river, cuts through the finer-grained sandstone. This deposit contains many tetrapods such as temnospondyls and archosauromorphs, but the fossils are part of a different faunal assemblage. [1]
The skull is about 3.5 centimetres (1.4 in) long, with a long and pointed snout. Silphedosuchus lacks the large canine teeth present in most other therocephalians, and has rounded crushing teeth at the back of the jaws with several cusps. Silphedosuchus has large orbits or eye sockets with raised edges. The eye socket is not entirely closed because the postorbital process, which forms the posterior margin of the orbit, does not reach the jugal bone below, which forms the bottom margin of the orbit. Characters that distinguish Silphedosuchus from Ericiolacerta include a narrow contact between the palatine and vomer bones on the roof of the mouth, a contact between the vomer and the maxilla that is positioned farther forward, and very wide buccal or cheek teeth. [1]
Ericiolacerta is an extinct genus of small therocephalian therapsids from the early Triassic of South Africa and Antarctica. It was around 20 centimetres (7.9 in) in length, with long limbs and relatively small teeth. It probably ate insects and other small invertebrates.
Therocephalia is an extinct suborder of eutheriodont therapsids from the Permian and Triassic. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their teeth, suggest that they were carnivores. Like other non-mammalian synapsids, therocephalians were once described as "mammal-like reptiles". Therocephalia is the group most closely related to the cynodonts, which gave rise to the mammals. This relationship takes evidence in a variety of skeletal features. The phylogeny of therocephalians has been disputed, as the monophyly of the group and the relationships of its members are unclear.
Mesosuchus is an extinct genus of basal Rhynchosaur from early Middle Triassic deposits of Eastern Cape, South Africa. It is known from the holotype SAM 5882, a partial skeleton, and from the paratypes SAM 6046, SAM 6536, SAM 7416 and SAM 7701 from the Aliwal North Euparkeria site. Mesosuchus is quite small, spanning around 30 cm in length. Mesosuchus was discovered and named by David Meredith Seares Watson in 1912.
Thalattosaurus (pron.:"tha-la-to-SORE-us") meaning "ocean lizard" is an extinct genus of marine reptile in the family Thalattosauridae. They were aquatic diapsids that are known exclusively from the Triassic period. It was a 2 metres (6.6 ft) long shellfish-eating reptile with paddle-like limbs and a down-turned rostrum occurring in the Lower and Middle Triassic Sulphur Mountain Formation of British Columbia as well as the Upper Triassic Hosselkus Limestone of California. It has gained notoriety as a result of studies on general diapsid phylogeny.
Moschorhinus is an extinct genus of therocephalian in the family Akidnognathidae, with only one species: M. kitchingi. It was a carnivorous, lion-sized synapsis which has been found in the Late Permian to Early Triassic of the South African Karoo Supergroup. It had a broad, blunt snout which bore long, straight canines. It appears to have replaced the gorgonopsids ecologically, and hunted much like a big cat. While most abundant in the Late Permian, it survived a little after the Permian Extinction, though these Triassic individuals had stunted growth.
Theriognathus is an extinct genus of therocephalian therapsid belonging to the family Whaitsiidae, from South Africa and Tanzania. Theriognathus has been dated as existing during the Late Permian. Although Theriognathus means mammal jaw, the lower jaw is actually made up of several bones as seen in modern reptiles, in contrast to mammals. Theriognathus displayed many different reptilian and mammalian characteristics. For example, Theriognathus had canine teeth like mammals, and a secondary palate, multiple bones in the mandible, and a typical reptilian jaw joint, all characteristics of reptiles. It is speculated that Theriognathus was either carnivorous or omnivorous based on its teeth, and was suited to hunting small prey in undergrowth. This synapsid adopted a sleek profile of a mammalian predator, with a narrow snout and around 1 meter long. Theriognathus is represented by 56 specimens in the fossil record.
Konzhukovia is an amphibian genus that belongs to an extinct group of temnospondyls, the largest clade of basal tetrapods including about 198 genera, 292 species, and more than half of which were alive during the early Mesozoic period. The animal was a predator that lived about 260 million years ago, and could get up to about 3 meters in length. Specifically, Konzukovia lived during the Permian, between 252 and 270 million years ago according to the type of rock the fossil was found in. There are three species within this genus, K. vetusta, K. tarda, and K. sangabrielensis, the first two originating from Russia while the latest originating from Southern Brazil. The discovery of this specimen in Southern Brazil provided more evidence to support the idea that during this animals existence, there was a “biological corridor” because of the supercontinent Pangea, allowing these species to be found so far apart from each other. Konzhukovia belongs to the family Archegosauridae, a family consisted of large temnospondyls that most likely compare to modern day crocodiles. Since the discovery of the latest species, K. sangabrielensis Pacheco proposes that there must be the creation of a new family, Konzhokoviidae, a monophyletic group in a sister-group relationship with Stereospondlyi in order to accommodate the three species. Konzhukovia skulls usually exhibit typical rhinesuchid features including an overall parabolic shape, small orbits located more posteriorly, and the pterygoids do not reach the vomer. These animals were long-snouted amphibians that had clear adaptations made for fish catching, as well as exemplifying aquatic features.
Microgomphodon is an extinct genus of therocephalian therapsid from the Middle Triassic of South Africa and Namibia. Currently only one species of Microgomphodon, M. oligocynus, is recognized. With fossils present in the Cynognathus Assemblage Zone (CAZ) of the Burgersdorp Formation in South Africa and Omingonde Formation of Namibia and ranging in age from late Olenekian to Anisian, it is one of the most geographically and temporally widespread therocephalian species. Moreover, its occurrence in the upper Omigonde Formation of Namibia makes Microgomphodon the latest-surviving therocephalian. Microgomphodon is a member of the family Bauriidae and a close relative of Bauria, another South African bauriid from the CAZ. Like other bauriids, it possesses several mammal-like features such as a secondary palate and broad, molar-like postcanine teeth, all of which evolved independently from mammals.
Vritramimosaurus is an extinct genus of large early archosauromorph. Although originally placed in the family Prolacertidae, recent studies on archosauromorph relationships doubt the validity of the family, at least in its broadest sense. Fossils have been found from Early Triassic deposits of the Rassypnaya locality in Orenburg Oblast, Russia. Rassypnaya is located on the Obshchy Syrt, a plateau in the European part of Russia that extends southwest of the Urals toward the Volga River. Vritramimosaurus is similar to the later genus Malutinisuchus, also from Rassypnaya but present in Middle Triassic deposits.
Daemonosaurus (pron.:"DAY-mow-no-SORE-us") is an extinct genus of theropod dinosaur from the Late Triassic of New Mexico. Fossils have been found from deposits in the Chinle Formation, which is latest Triassic in age. While theropods had diversified into several specialized groups by this time, Daemonosaurus is a basal theropod that lies outside the clade Neotheropoda. Daemonosaurus is unusual among early theropods in that it had a short skull and long protruding teeth.
Jesairosaurus is an extinct genus of early archosauromorph reptile known from the Illizi Province of Algeria. Although a relative of the long-necked tanystropheids, this gracile genus could instead be characterized by its relatively short neck as well as various skull features.
Arachana is an extinct genus of rhinesuchid-like temnospondyl known from the Late Permian or Early Triassic 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.
Purlovia is an extinct genus of herbivorous therocephalian therapsids from the Late Permian of Russia. Together with the closely related South African genus Nanictidops, it is a member of the family Nanictidopidae. Fossils have been found from the Tonshayevsky District of Nizhny Novgorod Oblast. The type species of Purlovia, P. maxima, was named in 2011.
Nanictidopidae is an extinct family of therocephalian therapsids from the Late Permian. Two genera are currently included in the family, Nanictidops from South Africa and Purlovia from Russia. Nanictidopids have short skulls and were probably herbivorous.
Blattoidealestes is an extinct genus of therocephalian therapsid from the Middle Permian of South Africa. The type species Blattoidealestes gracilis was named by South African paleontologist Lieuwe Dirk Boonstra from the Tapinocephalus Assemblage Zone in 1954. Dating back to the Middle Permian, Blattoidealestes is one of the oldest therocephalians. It is similar in appearance to the small therocephalian Perplexisaurus from Russia, and may be closely related.
Karenites is an extinct genus of therocephalian therapsids from the Late Permian of Russia. The only species is Karenites ornamentatus, named in 1995. Several fossil specimens are known from the town of Kotelnich in Kirov Oblast.
Urumchia is an extinct genus of therocephalian therapsids from the Early Triassic of China. The type species Urumchia lii was described by Chinese paleontologist C. C. Young in 1952 from the Jiucaiyuan Formation in Xinjiang. The holotype skull has been lost, but Young was able to describe the species on the basis of a detailed cast of the skull. Urumchia is similar to the South African therocephalian Regisaurus in having an expanded pair of vomer bones on the underside of the skull that form a secondary palate. In Urumchia the front end of the vomers narrow to a point, while in Regisaurus they do not. Urumchia has six incisors on either side of the upper jaw, a primitive condition among baurioid therocephalians that usually have fewer incisors.
Yikezhaogia is an extinct genus of therocephalian therapsids from the Early Triassic of Mongolia. It is known from a single fragmentary skull and associated postcranial bones representing the species Yikezhaogia megafenestrala. It is identifiable as a therocephalian by its thin postorbital bar behind the eye socket, its elongated temporal opening behind the bar, and a thin lower jaw with a low coronoid process. Large tooth sockets in the upper jaw indicate that Yikezhaogia had large caniniform teeth. The teeth of the lower jaw are blunt-tipped and cylindrical. Although its exact position among therocephalians is uncertain, Yikezhaogia is probably a basal member of the group Baurioidea.
Teyujagua is an extinct genus of small, probably semi-aquatic archosauromorph reptile that lived in Brazil during the Early Triassic period. The genus contains the type and only known species, T. paradoxa. It is known from a well-preserved skull, and probably resembled a crocodile in appearance. It was an intermediary between the primitive archosauromorphs and the more advanced Archosauriformes, revealing the mosaic evolution of how the key features of the archosauriform skull were acquired. Teyujagua also provides additional support for a two-phase model of archosauriform radiation, with an initial diversification in the Permian followed by a second adaptive radiation in the Early Triassic.
Kadimakara is an extinct genus of early archosauromorph reptile from the Arcadia Formation of Queensland, Australia. It was seemingly a very close relative of Prolacerta, a carnivorous reptile which possessed a moderately long neck. The generic name Kadimakara references prehistoric creatures from Aboriginal myths which may have been inspired by ice-age megafauna. The specific name K. australiensis relates to the fact that it was found in Australia. Prolacerta and Kadimakara were closely related to the Archosauriformes, a successful group which includes archosaurs such as crocodilians, pterosaurs, and dinosaurs.
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