''Parasaurus'' (meaning "near lizard") is a genus of pareiasaur known from fossils collected in the

Kupferschiefer The Kupferschiefer (German for Copper Shale, also called Copper Slate) or Kupfermergel (Copper Marl), (T1 or Z1) is an extensive and remarkable sedimentary unit in Central Europe. The relatively monotonous succession is typically and maximum th ...

Germany Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...

(

Hesse Hesse (, , ) or Hessia (, ; german: Hessen ), officially the State of Hessen (german: links=no, Land Hessen), is a state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt. Two other major historic cities are Da ...

Thuringia Thuringia (; german: Thüringen ), officially the Free State of Thuringia ( ), is a state of central Germany, covering , the sixth smallest of the sixteen German states. It has a population of about 2.1 million. Erfurt is the capital and lar ...

and

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), dating to the Late Permian ( Wuchiapingian). The type species, ''Parasaurus geinitzi'', described by Hermann von Meyer in 1857, was the first pareiasaur ever described. The seven known specimens were redescribed in 2008.L. A. Tsuji and J. Müller. (2008). A Re-evaluation of ''Parasaurus geinitzi'', the first named pareiasaur (Amniota, Parareptilia). Canadian Journal of Earth Sciences 45(10):1111-1121

Discovery and naming

As early as 1848, pareiasaur

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s have been reported from Germany; some of these fossils may have belonged to ''Parasaurus''. It was not until 1857 when von Meyer described these fossils and created the ''Parasaurus'' genus.Meyer, H.V. (1857). Beiträge zur näheren Kenntnis fossiler Reptilien. ''Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde'', 1857: 103–104. von Meyer classified ''Parasaurus'' as a reptile but it was classified as a pareiasaur when the family was created in 1888. Lee (1997) classified ''Parasaurus'' as a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

''. In 2008, Tsuji and Müller re-evaluated the genus.

Description

''Parasaurus'' was small for a pareiasaur, only around long. Axial osteoderms appear to be absent. The skull surface is pitted, with small spike-like horns on the supratemporal and quadratojugal.

Phylogeny

Below is a

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

from Tsuji ''et al.'' (2013):

Paleoenvironment

The Kupferschiefer is a marine unit that forms part of the

Zechstein The Zechstein (German either from ''mine stone'' or ''tough stone'') is a unit of sedimentary rock layers of Middle to Late Permian ( Guadalupian to Lopingian) age located in the European Permian Basin which stretches from the east coast of Engl ...

, a sequence of rocks formed on the edge of the Zechstein Sea, a large inland shallow sea that existed in Northern Europe during the Late Permian. The environment at the time of deposition is considered to have been

semi-arid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi- ...

. The terrestrial flora of the Zechstein is dominated by conifers, with seed ferns also being common, while taeniopterids, ginkgophytes and sphenophytes are rare. Other terrestrial vertebrates found in the Kupferschiefer and lower Zechstein include the gliding

weigeltisaurid Weigeltisauridae is a family of gliding neodiapsid reptiles that lived during the Late Permian, between 258 and 252 million years ago. Fossils of weigeltisaurids have been found in Madagascar, Germany, Great Britain, and Russia. A possible weigelt ...

reptiles '' Weigeltisaurus'' and '' Glaurung,'' the archosauromorph reptile '' Protorosaurus,'' the

cynodont The cynodonts () ( clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variet ...

'' Procynosuchus,'' and indeterminate captorhinids,

dicynodonts Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typica ...

, and

dissorophid Dissorophidae is an extinct family of medium-sized, temnospondyl amphibians that flourished during the late Carboniferous and early Permian periods. The clade is known almost exclusively from North America. History of study Dissorophidae is a ...

temnospondyls.

References

{{Taxonbar, from=Q21368822 Pareiasaurs Nomina dubia Fossil taxa described in 1857 Prehistoric reptile genera