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''Parasaurus'' (meaning "near lizard") is a genus of
pareiasaur Pareiasaurs (meaning "cheek lizards") are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with scutes which covered large areas of the body. They first appeared in southern Pangea during the Middle Permian, ...
known from fossils collected in the Kupferschiefer in
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
(
Hesse Hesse (, , ) or Hessia (, ; german: Hessen ), officially the State of Hessen (german: links=no, Land Hessen), is a States of Germany, state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt. Two other major histor ...
,
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 larg ...
and
Lower Saxony Lower Saxony (german: Niedersachsen ; nds, Neddersassen; stq, Läichsaksen) is a German state (') in northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ...
), dating to the Late Permian (
Wuchiapingian In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or Series. The ...
). The type species, ''Parasaurus geinitzi'', described by
Hermann von Meyer Christian Erich Hermann von Meyer (3 September 1801 – 2 April 1869), known as Hermann von Meyer, was a German palaeontologist. He was awarded the 1858 Wollaston medal by the Geological Society of London. Life He was born at Frankfurt am Ma ...
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 Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...
but it was classified as a pareiasaur when the family was created in 1888. Lee (1997) classified ''Parasaurus'' as a '' nomen dubium''. 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 The supratemporal bone is a paired cranial bone present in many tetrapods and tetrapodomorph fish. It is part of the temporal region (the portion of the skull roof behind the eyes), usually lying medial (inwards) relative to the squamosal and latera ...
and
quadratojugal The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians. Anatomy and function In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front and ...
.


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 d ...
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 Englan ...
, 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-ar ...
. 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 reptiles ''
Weigeltisaurus ''Weigeltisaurus'' is an extinct genus of weigeltisaurid reptile from the Late Permian Kupferschiefer of Germany and Marl Slate of England. It has a single species, originally named as ''Palaechamaeleo jaekeli'' in 1930 and later assigned the na ...
'' and ''
Glaurung J. R. R. Tolkien's Middle-earth legendarium features dragons based on those of European legend, but going beyond them in having personalities of their own, such as the wily Smaug, who has features of both Fafnir and the ''Beowulf'' dragon. ...
,'' the archosauromorph reptile ''
Protorosaurus ''Protorosaurus'' ("first lizard") is a genus of lizard-like early reptiles. Members of the genus lived during the late Permian period in what is now Germany and Great Britain. Once believed to have been an ancestor to lizards, ''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 variety ...
''
Procynosuchus ''Procynosuchus'' (Greek: "Before dog crocodile") is an extinct genus of cynodonts from the Late Permian. It is considered to be one of the earliest and most basal cynodonts. It was 60 cm (2 ft) long. Remains of ''Procynosuchus'' have ...
,'' and indeterminate
captorhinids Captorhinidae (also known as cotylosaurs) is an extinct family of tetrapods, traditionally considered primitive reptiles, known from the late Carboniferous to the Late Permian. They had a cosmopolitan distribution across Pangea. Description C ...
,
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, typicall ...
, and dissorophid
temnospondyls Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carbo ...
.


References

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