The Pareiasaurs (Pareiasauridae) are a clade of medium-sized to large herbivorous anapsid (turtles ancestors) reptiles that flourished during the Permian period. Their build was quite stocky, often with rather short tails and small heads. These ungainly-looking animals had very large bodies, ranging from 60 to 300 centimetres (2.0 to 9.8 ft) long, and weights of 600 kilograms (1,300 lb) would not have been unusual. They also had strong limbs, broad feet, and short tails. They were protected with bony scutes (osteoderms) set in the skin, as a defense against predators. Their heavy skulls were ornamented with multiple knobs and ridges. The leaf-shaped multi-cusped teeth resemble those of iguanas, caseids, and other reptilian herbivores. This dentition, together with the deep capacious body, which could have housed an extensive digestive tract, indicate that these fearsome-looking animals were herbivores. Michael Lee has argued that pareiasaurs include the direct ancestors of modern turtles. They had turtle-like skull features, and in several genera the scutes had developed into bony plates, possibly the precursors of a turtle shell. Jalil and Janvier, in a large analysis of pareiasaur relationships, also found turtles to be close relatives of the "dwarf" pareiasaurs, such as Pumiliopareia. However, the exact relationships of turtles remains controversial, and critics have argued that pareiasaur scutes are not homologous with the turtle shell.
Bradysaurus was a large (2.5 to 3 meters long [8 to 10 ft]), early and common pareiasaur, the fossils of which are known from the richly fossiliferous 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. In life they were probably slow, clumsy and inoffensive animals, that had evolved a covering of armoured scutes to protect them against their predators, the gorgonopsians.
The skull was large (about 42 to 48 centimeters long [17 to 19 in]), 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 would seem to be synonyms of Bradysaurus.The two species are as follows:
- B.Baini (Seeley, 1892): 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):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.
The skull of this pareiasaur is unknown. It is known from a number of isolated vertebrae, jaws, and limb-bones and an incomplete skeleton, all from a single locality. Shihtienfenia is unusual because of the presence of 6, rather than the usual 4, sacral vertebrae, and may belong in a separate subfamily, although Oskar Kuhn includes it under the Pareiasaurines in his monograph. As with the Pareiasaurines the upper margin of the ilium is flat. No dicynodonts are found in association, so these animals obviously lived in a separate environment. Shihtienfenia Permica was classified as a pareiasaur by M. S. Y. Lee in 1997. Shihtienfenia Permica may belong under a different subfamily in Pareiasauridae, but Oskar Kuhn put it under Pareiasaurinae in his monograph. Shihtienfenia, and the members of Pareiasaurinae have flat upper margins of the ilium.
Deltavjatia was a procolophonid reptile from the Tatarian stage of the Permian time period, It was an herbivore, meaning that it only ate plants, those creatures lived in what is now Russia. Deltavjatia was named a subtaxon of Pareiasauridae by M.S.Y. Lee in 1997. Pareiasuchus vjatkensis is the alternative combination of Deltavjatia vjatkensis. It also was named Anthodon rossicus by Hartmann & Weinberg in 1937. The first specimen of Deltavjatia was a specimen of a skull and lower mandobile, found in the Urpalov Formation in Kotelnich, Vyatka River. It was named Deltavjatia vjatkensis by Hartmann & Weinberg in 1937.
Embrithosaurus is a genus of permian pareiasaurs found on South Africa, Russia, and Mongolia. Their species includes E.shwarzi, E.strubeni, E.angustus, & E. alexandri.
- Embrithosaurus schwarzi is the type species of Embrithosaurus. The smooth dermal plates and the nine cusps in its teeth suggest it was also the most advanced.
- Embrithosaurus strubeni was originally the type species of Embrithosaurus's synonym, Nochelosaurus by Haughton & Boonstra. In 1969, Boonstra thought it belonged under the Bradysaurus genus. But Kuhn thought that it belonged under the Embrithosaurus genus. Their skull is large and deep, and high in the jugal region.
- Embrithosaurus angustus was named the type species for Embrithosaurus's synonym Dolichoparia, their skull is long and narrow, indicating that it might have had a different diet than other pareiasaurs.
Anthodon and Nanopareia
Anthodon and Nanopareia are two extinct genus of permian anapsid pareiasaurs, they belong to an unranked taxon named Pumiliopareiasauria. Those reptiles was the turtle's direct ancestors.
- Anthodon (flower tooth) was found in South Africa, Tanzania, and possibly northern Russia. It was about 1.2 to 1.5 meters in length (3.9 to 4.9 ft), and weighed around 80 to 100 kilograms (176 to 220 lb). The skull was small, and the cheekbones unornamented as in other pareiasaurids. Richard Owen, who described Anthodon, thought it was a dinosaur because dinosaurian skull material from the Early Cretaceous had become associated with the Permian material. The dinosaur material was later separated out by Robert Broom in 1912 and was renamed as the stegosaurid Paranthodon by Franz Nopcsa in 1929. There are four species, Anthodon serrarius, A. gregoryi, A. minisculus, and, A. rossicus (also named Pareiasuchus vjatkensis)
Elginia was a genus of Late Permian pareisaurs, which normally grew up to 3 metres (9.8 ft).It was a dwarf genus of pareiasaur, only about 60 centimetres (2 ft) long, with fossils found at Elgin in Scotland. Its head was covered in spikes, with the longest pair growing out of the back of the skull. These spikes were probably used for display rather than physical combat.
Pareiasuchus was a genus of herbivore permian pareiasaur reptiles found on South Africa and Zambia. Pareiasuchus was named a pareiasaur by M.S.Y. Lee in 1997.
Pareiasaurus is an extinct genus of permian anapsid reptiles. It was a typical member of its family, the pareiasaurs, which take their name from this genus.They are large quadruped, about 2.5 metres (8.2 ft) long, with elephantine legs, walking in a typically reptilian posture. Its skull had several spine- and wart-like protrusions. Pareiasaurus's leaf-shaped teeth, ideal for biting through tough plant fibers, indicate it was a herbivore. Even the palate had teeth. Their species include: Pareiasaurus serridens, P. baini, P. bombidens, P. russouwi.
thumb|300px|right|Scutosaurus in Walking With Monsters Series. (From 1:30 to end). Scutosaurus (Shield Lizard) was a genus of armor-covered pareiasaur that lived around 252-248 million years ago in Russia, in the later Permian period. 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.
- Paleobiology: Scutosaurus karpinskii was a massively built reptile, up to 2.5 metres (8.2 ft) in length, with bony armor, and a number of spikes decorating its skull. Despite its relatively small size, Scutosaurus was heavy, and its short legs meant that it could not move at speed for long periods of time, which made it vulnerable to attack by large predators. To defend itself Scutosaurus had a thick skeleton covered with powerful muscles, especially in the neck region. Underneath the skin were rows of hard, bony plates (scutes) that acted like a form of chain mail.As a plant-eater living in a semi-arid climate, Scutosaurus would have wandered widely in order find fresh foliage to eat. It may have stuck closely to the riverbanks and floodplains where plant life would have been more abundant, straying further afield only during times of drought. Its teeth were flattened and could grind away at the leaves and young branches before digesting them at length in its large gut. Given that it needed to eat constantly, Scutosaurus probably lived alone, or in very small herds, so as to avoid denuding large areas of their edible plants. With its large cheekbones, Scutosaurus may have been able to make a loud bellowing sound. It had excellent hearing and could have heard other animals bellowing from some distance away. These noises could have been used for mating or as warning signals.
- In the media: Scutosaurus was shown in the Walking with Monsters series as being a social animal that migrated in groups. Scutosaurus was depicted as being the main prey of a large gorgonopsid, later erroneously identified in the books as Gorgonops. It was highly unlikely that Gorgonops preyed on these beasts, as it was indigenous to the region in Gondwana that is now South Africa, while Scutosaurus was indigenous to the region in Laurasia that is now Siberia. However, it is possible that related animals, such as the Russian Inostrancevia, may have preyed on Scutosaurus. Scutosaurus was also shown in the Primeval series, on the oficial page depicts "A large passive herbivore, Scutosaurus—literally "shield lizard"—weighs about 5.5 tons. Loosely related to the turtle, this creature is based on a heavily armored reptile called Scutosaurus kapinskii, which lived 250 million years ago in Russia. Smaller than its fictional counterpart, the real species, probably weighed closer to one ton. Because of its plant-based diet, Scutosaurus likely lived near riverbanks and floodplains." Scutosaurus is also a Zoo Tycoon 2 creature.
Pareiasaurs and Turtles
Their exact ancestry has been disputed. It was believed they are the only surviving branch of the ancient evolutionary grade Anapsida, which includes groups such as procolophonids, millerettids, protorothyrids, and pareiasaurs. All anapsid skulls lack a temporal opening, while all other extant amniotes have temporal openings (although in mammals the hole has become the zygomatic arch). The millerettids, protorothyrids, and pareiasaurs became extinct in the late Permian period, and the procolophonoids during the Triassic