Gorgonopsia

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Gorgonopsia
Fossil range: Middle - Late Permian

Restoration of Inostrancevia

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Synapsida
Order:	Therapsida
(unranked)	Theriodontia
Suborder:	Gorgonopsia Seeley, 1895
Family:	Gorgonopsidae Lydekker, 1890

Gorgonops as seen in Walking with Monsters

Gorgonopsia ("Gorgon face") is a suborder of synapsids. Cladistically, synapsids include mammals, although they were previously considered reptiles. Their name is a reference to the Gorgons of Greek mythology, renowned for their fearsome power.

1 Characteristics
2 Evolutionary history
3 Taxonomy
4 Popular Culture
5 References
6 See also

[edit] Characteristics

They are officially recognised as mammal-like reptiles, although more and more they are being considered as reptile-like mammals, due to the large number of mammalian adaptations, and very few remaining reptile-like traits. Their mammalian specialisations include differentiated tooth shape, the fully developed temporal fenestra, pillar-like rear legs and even ear bones. Gorgonopsians are a part of a special group of therapsids called theriodonts, which included mammals. They were among the largest carnivores of the late Permian. The largest known, Inostrancevia, was the size of a large bear with a 45 cm long skull, and 12 cm long sabre-like teeth (clearly an adaptation to being a carnivore). It is unknown whether they had fur, scales, or naked skin.

The group perished during the end Permian mass extinction.

The gorgonopsians are one of the three groups of theriodonts (the other two were the therocephalians, and the cynodonts). Theriodonts are related to the herbivorous Anomodontia.

Gorgonopsia includes three subfamilies, the Gorgonopsinae, Rubidgeinae and Inostranceviinae, plus a larger number of genera that have not been placed in any of these groups. A total of 25 genera and 41 species, with the genera described most completely being Dinogorgon, Inostrancevia and Rubidgea.

The most comprehensive review of the group is by Sigogneau-Russell, 1989. However, there has not been a detailed cladistic assessment of the phylogeny of these animals.

[edit] Evolutionary history

Gorgonopsids (Gorgonopsia) are theriodonts of the therapsid order, to which cynodonts and their descendants, the mammals, belong. The Gorgonopsians evolved from a reptile-like therapsid that lived in the Middle Permian. The early gorgonopsians were small, being no larger than a dog. The extinction of dinocephalians (who dominated the Middle Permian world) led the gorgonopsians to be the dominant predators of the Late Permian. In the Late Permian many gorgonopsians grew to the size of large dogs and cows. Some had approached the size of a rhinoceros, such as Inostrancevia, the largest of the Gorgonopsians. The Gorgonopsia became extinct at the end of the Permian period.

[edit] Taxonomy

Order Therapsida
SUBORDER GORGONOPSIA
- Family Gorgonopsidae
  - Aelurognathus
  - Aelurosaurus
  - Aloposaurus
  - Arctognathus
  - Arctops
  - Broomisaurus
  - Cephalicustroidus
  - Cerdorhinus
  - Clelandina
  - Cyanosaurus
  - Dinogorgon
  - Eoarctops
  - Galesuchus
  - Gorgonops
  - Leontocephalus
  - Lycaenops
  - Paragalerhinus
  - Scylacognathus
  - Sycosaurus
  - Subfamily Gorgonopsinae
    - Sauroctonus
    - Scylacops
  - Subfamily Rubidgeinae
    - Broomicephalus
    - Niuksenitia
    - Prorubidgea
    - Rubidgea
  - Subfamily Inostranceviinae
    - Pravoslavleria
    - Inostrancevia

[edit] Popular Culture

Gogonopsids have appeared in several TV shows animated by Framestore CFC. It appeared in the third episode of Walking With Monsters, and more recently in several episodes of Primeval. In the first episode it was the principal monster, attacking humans on several occasions until being gunned down. In the series finale another one appeared, battling and emerging victorious against a predator from the future. In both series it is always referred to as a Gorgonopsid, regardless of its exact species.

[edit] References

Bakker, R.T. (1986), The Dinosaur Heresies, Kensington Publishing Corp.
Cox, B. and Savage, R.J.G. and Gardiner, B. and Harrison, C. and Palmer, D. (1988) The Marshall illustrated encyclopedia of dinosaurs & prehistoric animals, 2nd Edition, Marshall Publishing
Fenton, C.L. and Fenton, M.A. (1958) The Fossil Book, Doubleday Publishing
Hore, P.M. (2005), The Dinosaur Age, Issue #18. National Dinosaur Museum
Sigogneau-Russell, D., 1989, "Theriodontia I - Phthinosuchia, Biarmosuchia, Eotitanosuchia, Gorgonopsia" Part 17 B I, Encyclopedia of Paleoherpetology, Gutsav Fischer Verlag, Stuttgart and New York
Ward, P.D. (2004), Gorgon, Viking Penguin