''Pareiasaurus'' (from , "cheek" and , "lizard") is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus of pareiasauromorph

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

from the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

period. It was a typical member of its

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

, the pareiasaurids, which take their name from this

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

. Fossils have been found in the Beaufort Group.

Description

''Pareiasaurus'' is a large

quadruped Quadrupedalism is a form of locomotion in which animals have four legs that are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four legs is said to be a quadruped (fr ...

, about long, with

elephant Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant ('' Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant ('' Elephas maximus ...

ine legs, walking in a typically reptilian posture. The skull is broad and the snout short. Its skull had several spine- and wart-like protrusions. ''Pareiasauruss

leaf A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leav ...

-shaped

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

, ideal for biting through tough

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

fibers, indicate it was a herbivore. Even the

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sep ...

had teeth.

Species

''P. nasicornis'' (Haughton and Boonstra, 1929) is from the ''Tropidostoma'' Zone, Karoo basin, South Africa. This early form is one of the first representatives of the genus. It was originally included under the genus ''Pareiasuchus''. The snout is heavily armoured, and bears a horn-like boss. The teeth are equipped with 11 (or possibly 13 or 15) cusps. This is a large animal; the skull is about 50 cm in length. This species might be ancestral to ''Pareiasaurus peringueyi''. ''P. peringueyi'' (Haughton and Boonstra, 1929) is from the ''Cistecephalus'' Zone, Karoo basin, South Africa. It is represented by a nearly complete skeleton from the Zak River, South Africa. It is a medium-sized animal, the skull being 36 cm long. It is distinguished especially by the large quadrato-jugal region inclined far outwards and forwards so that its lower border makes an angle of about 120° with the maxillary border; this cheek bears large bony bosses. There are at least 13 pairs of teeth in the upper jaw, each with 13 or possibly 15 cusps. ''P. serridens'' (Owen, 1876) is from the ''Dicynodon'' Zone, Karoo basin, South Africa. This species was the type species for ''Pareiasuchus''. This late species is the type species for ''Pareiasaurus'', and represents the culmination of this lineage. The armour is well developed. There are 14 pairs of teeth, each with 9 to 11 cusps. The short deep skull is about 40 cm in length. Note the extended quadrato-jugal region (cheek bones).

References

External links

Pareiasaurinae
at Palaeos Pareiasauria Permian reptiles of Africa Permian reptiles of Europe Fossil taxa described in 1876 Lopingian life Wuchiapingian life Changhsingian life Wuchiapingian genus first appearances Changhsingian genus extinctions Prehistoric reptile genera {{permian-reptile-stub