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Bradysaurus Temporal range: Capitanian, | |
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Skeleton in the Field Museum | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | † Parareptilia |
Order: | † Procolophonomorpha |
Clade: | † Pareiasauria |
Family: | † Pareiasauridae |
Subfamily: | † Bradysaurinae von Huene, 1948 |
Genus: | † Bradysaurus Watson, 1914 |
Type species | |
†Bradysaurus baini Seeley, 1892 | |
Species | |
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Synonyms | |
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Bradysaurus was a large, early and common pareiasaur. They possessed a covering of armoured scutes, likely serving as defense against their main predators, the gorgonopsians.
Fossils of Bradysaurus are known from the Tapinocephalus Assemblage Zone (Capitanian age) of the South African Karoo. Along with the similarly large dinocephalia, the bradysaurs constituted the herbivorous megafauna of the late Middle Permian Period.
Bradysaurus was 2.5–3 m (8 ft 2 in – 9 ft 10 in) in length [1] and half a tonne to a tonne in weight. The skull was large (about 42 to 48 centimeters long), broad and rounded at the front. It was coarsely sculptured and knobby, with the sutures between the bones not clearly visible. The marginal teeth were high-crowned, with only a few cusps, which is a primitive characteristic. The feet were short and broad, the phalangeal count being 2,3,3,3,2 on the fore-foot and 2,3,3,4,3 on the hind. The whole body is protected by dermal scutes, although these are not as thick or heavy as in more advanced forms.
Bradysaurus is the only member of the subfamily Bradysaurinae. It is the most primitive known pareiasaur and can be considered a good ancestral type from which the others developed. Its large dimensions show that, even very early in their evolutionary history, these strange animals had already attained an optimal size. Even later, more advanced forms, like Scutosaurus , were no larger. The advantage of large size was to provide defense against predators and to maintain a stable body temperature (gigantothermy).
Kuhn 1969 lists no fewer than nine species for this genus, but this is certainly an excessive number. Boonstra 1969 distinguishes only four species on the basis of tooth structure, two of which Kuhn places in the genus Embrithosaurus. The genera Brachypareia, Bradysuchus, Koalemasaurus, and Platyoropha are synonyms of Bradysaurus.
B. baini (Seeley, 1892) is from the Tapinocephalus zone, Lower Beaufort Beds, Karoo basin, South Africa. This is the type species for the genus. The quadra-jugal region (cheek-bones) were only moderately developed. The snout was broad and rounded and there were 15 or 16 pairs of overlapping teeth in each jaw. This animal could be considered a generic early pareiasaur. According to Lee, 1997, the available material of B. baini lacks distinguishing autapomorphies or characteristics.
B. seeleyi (Haughton and Boonstra, 1929) is from the Tapinocephalus zone, Lower Beaufort Beds, Karoo basin, South Africa. This is a less common form. Boonstra, 1969, considered this a valid species of Bradysaurus and Lee, 1997, considers this animal a sister group to more advanced pareiasaurs. B. seelyi seems to be closely related to Nochelesaurus and Embrithosaurus . In contrast to the more numerous but similarly sized B. baini, the cheekbones were heavy and greatly enlarged. There were 19 or 20 pairs of strongly overlapping teeth on each jaw.
Pareiasaurs are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with osteoderms which covered large areas of the body. They first appeared in southern Pangea during the Middle Permian, before becoming globally distributed during the Late Permian. Pareiasaurs were the largest reptiles of the Permian, reaching sizes equivalent to those of contemporary therapsids. Pareiasaurs became extinct in the Permian–Triassic extinction event.
Moschops is an extinct genus of therapsids that lived in the Guadalupian epoch, around 265–260 million years ago. They were heavily built plant eaters, and they may have lived partly in water, as hippopotamuses do. They had short, thick heads and might have competed by head-butting each other. Their elbow joints allowed them to walk with a more mammal-like gait rather than crawling. Their remains were found in the Karoo region of South Africa, belonging to the Tapinocephalus Assemblage Zone. Therapsids, such as Moschops, are synapsids, the dominant land animals in the Permian period, which ended 252 million years ago.
Robertia is an extinct genus of small herbivorous dicynodonts from the Middle to Late Permian of South Africa, between 260 and 265 million years ago. It is a monospecific genus, consisting of the type-species R. broomiana, which was classified by Lieuwe Dirk Boonstra in 1948 and named in honor of Robert Broom for his study of South African mammal-like reptiles.
Tapinocephalus is an extinct genus of large herbivorous dinocephalians that lived during the Middle Permian Period in what is now South Africa. Only the type species, Tapinocephalus atherstonei is now considered valid for this genus.
Gorgonops is an extinct genus of gorgonopsian therapsid, of which it is the type genus. Gorgonops lived during the Late Permian (Wuchiapingian), about 260–254 million years ago in what is now South Africa.
Scutosaurus is an extinct genus of pareiasaur parareptiles. Its genus name refers to large plates of armor scattered across its body. It was a large anapsid reptile that, unlike most reptiles, held its legs underneath its body to support its great weight. Fossils have been found in the Sokolki Assemblage Zone of the Malokinelskaya Formation in European Russia, close to the Ural Mountains, dating to the late Permian (Lopingian) between 264 and 252 million years ago.
Jonkeria is an extinct genus of dinocephalians. Species were very large and omnivorous, from the Tapinocephalus Assemblage Zone, Lower Beaufort Group, of the South African Karoo.
Tapinocephalidae is an extinct family of advanced tapinocephalians. It is defined as the clade containing Ulemosaurus, Tapinocaninus, and the Tapinocephalinae. They are known from both Russia and South Africa. In all probability, the Tapinocephalidae had a worldwide (Pangean) distribution. They flourished briefly during the Wordian and Capitanian ages, radiating into several lineages, existing simultaneously, and differing mainly in details of the skull and, to an even lesser degree, the skeleton. It is not clear how such similar animals could each find their own ecological niche, but such was obviously the case. There is a parallel here with the hadrosaur and ceratopsian dinosaurs of the Late Cretaceous. The cause of their abrupt extinction is not clear, since other smaller animals, and even the pareiasaurs, were not affected. Quite probably, like the extinction of the late Pleistocene megafauna, a number of factors were involved.
Pareiasaurus is an extinct genus of pareiasauromorph reptile from the Permian period. It was a typical member of its family, the pareiasaurids, which take their name from this genus.
Anteosaurus is an extinct genus of large carnivorous dinocephalian synapsid. It lived at the end of the Guadalupian during the Capitanian stage, about 265 to 260 million years ago in what is now South Africa. It is mainly known by cranial remains and few postcranial bones. Measuring 5–6 m (16–20 ft) long and weighing about 600 kg (1,300 lb), Anteosaurus was the largest known carnivorous non-mammalian synapsid and the largest terrestrial predator of the Permian period. Occupying the top of the food chain in the Middle Permian, its skull, jaws and teeth show adaptations to capture large prey like the giants titanosuchids and tapinocephalids dinocephalians and large pareiasaurs.
The Tapinocephalus Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the middle Abrahamskraal Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching approximately 2,000 metres (6,600 ft), occur from Merweville and Leeu-Gamka in its southernmost exposures, from Sutherland through to Beaufort West where outcrops start to only be found in the south-east, north of Oudshoorn and Willowmore, reaching up to areas south of Graaff-Reinet. Its northernmost exposures occur around the towns Fraserburg and Victoria West. The Tapinocephalus Assemblage Zone is the second biozone of the Beaufort Group.
The Pristerognathus Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the upper Abrahamskraal Formation and lowermost Teekloof Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching not more than 300 metres (980 ft), occur just east of Sutherland through to Beaufort West in the south and Victoria West in the north. Exposures are also found west of Colesberg and south of Graaff-Reinet. The Pristerognathus Assemblage Zone is the third biozone of the Beaufort Group.
Struthiocephalus is an extinct genus of dinocephalian therapsids from the Permian of South Africa. It was a large animal, reaching 288 kg (635 lb) in body mass.
Styracocephalus platyrhynchus is an extinct genus of dinocephalian therapsid that existed during the mid-Permian throughout South Africa, but mainly in the Karoo Basin. It is often referred to by its single known species Styracocephalus platyrhynchus. The Dinocephalia clade consisted of the largest land vertebrates and herbivores during the early to mid-Permian. This period is often also referred to as the Guadalupian epoch, approximately 270 to 260 million years ago.
Aelurosaurus is a small, carnivorous, extinct genus of gorgonopsian therapsids from the Late Permian of South Africa. It was discovered in the Karoo Basin of South Africa, and first named by Richard Owen in 1881. It was named so because it appeared to be an ancestor for cat-like marsupials, but not yet a mammal itself. It contains five species, A. felinus, A. whaitsi, A. polyodon, A. wilmanae, and A.? watermeyeri. A. felinus, the type species, is generally well described with established features, while the other four species are not due to their poorly preserved holotypes.
Scymnosaurus is a dubious genus of therocephalian therapsids based upon various fossils of large early therocephalians. The genus was described by Robert Broom in 1903 with S. ferox, followed by S. watsoni in 1915 and a third, S. major, by Lieuwe Dirk Boonstra in 1954. Each of these species are considered nomen dubia today and based upon specimens belonging to two separate families of therocephalians. S. ferox and S. major represent specimens of Lycosuchidae incertae sedis, while S. watsoni is Scylacosauridae incertae sedis. Broom named a fourth species in 1907 from KwaZulu-Natal, S. warreni, though he later referred it to Moschorhinus as a valid species in 1932 but now is recognised as being synonymous with M. kitchingi.
Scullya is an extinct genus of titanosuchian therapsids. It is known from a poorly preserved snout that shows no clear titanosuchian characters. The presence of teeth on the palate may be an anteosaurian character. It is considered an indeterminable specimen.
Embrithosaurus was a pareiasaur from the Permian of South Africa.
Criocephalosaurus is an extinct genus of tapinocephalian therapsids that lived in Southern Africa during the Guadalupian epoch of the Permian. They are the latest surviving dinocephalians, extending past the Abrahamskraal Formation into the lowermost Poortjie Member of the Teekloof Formation in South Africa. They are also regarded as the most derived of the dinocephalians, alongside Tapinocephalus, and the most abundant in the fossil record.
Pareiasauromorpha is a group of parareptilian amniotes from the Permian. It includes genera found all over the world, with many genera from Asia and South Africa. The clade was first used as a group by Linda A. Tsuji in 2011, in order to group the family Nycteroleteridae (nycteroleters) and the superfamily Pareiasauroidea (pareiasaurs). Pareiasauromorpha is considered to be a monophyletic node, the sister group to procolophonoids.
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