Pareiasaur

Taxobox
name = Pareiasaurs
fossil_range = Mid - Late Permian

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image_width = 250px
image_caption = "Scutosaurus karpinskii" from the Late Permian of Russia
regnum = Animalia
phylum = Chordata
classis = Sauropsida
subclassis = Anapsida
ordo = Procolophonia
familia = Pareiasauridae
familia_authority = Lydekker, 1889
subdivision_ranks = Genera
subdivision = "Arganaceras"
"Bradysaurus"
"Nochelesaurus"
"Embrithosaurus"
"Deltavjatia"
"Velosauria"
"Shihtienfenia"
"Pareiasuchus"
"Pareiasaurus"
"Scutosaurus"
"Elginia"
"Nanopareia"

The Pareiasaurs - family Pareiasauridae - are a group of medium-sized to large herbivorous anapsid reptiles that flourished during the Permian period. Sizes of known Pareiasaurs was from (60 cm to 3 meters long). Their build was quite stocky, often with rather short tails and small heads. These ungainly-looking animals had very large bodies (weights of 600 kg would not have been unusual), strong limbs, broad feet, and short tails. They were protected with bony scutes (osteoderms) set in the skin, as a defense against predators. But the most unusual thing about them were the heavy skulls ornamented with strange 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 would have housed an extensive digestive tract) indicate that these fearsome-looking animals were herbivores.

Lee 1997 has argued that Pareiasaurs evolved into 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. However, critics have pointed out problems in this view, such as the non-homology between pareiasaur scutes and the turtle shell.

In fiction

In Edgar Rice Burroughs' novel Tarzan at the Earth's Core, the characters encounter Pareiasaurs in Pellucidar. They are called Gorobors by the native Pellucidarians. In the book they are portrayed as the fastest of all animals.

References / Links

* Carroll, R. L., (1988), "Vertebrate Paleontology and Evolution", W.H. Freeman & Co. New York, p.205
* deBraga, M. & Rieppel, O. (1997) Reptile phylogeny and the interrelationships of turtles, Z"ool. J. Linnean Soc." 120: 281-354.
* Kuhn, O, 1969, Cotylosauria, part 6 of "Handbuch der Palaoherpetologie" (Encyclopedia of Palaeoherpetology), Gustav Fischer Verlag, Stuttgart & Portland
* Laurin, M. (1996), " [http://www.ucmp.berkeley.edu/anapsids/pareiasauria.html Introduction to Pareiasauria - An Upper Permian group of Anapsids] "
* Lee, M.S.Y. (1997), Pareiasaur phylogeny and the origin of turtles. "Zool. J. Linnean Soc.", 120: 197-280
* Mikko's Phylogeny Archive [http://www.fmnh.helsinki.fi/users/haaramo/Metazoa/Deuterostoma/Chordata/Reptilia/Parareptilia/Hallucicrania.htm Hallucicrania - Pareiasauriformes]
* Palaeos [http://www.palaeos.com/Vertebrates/Units/Unit200/200.html Anapsida: Hallucicrania]