Inostrancevia

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Inostrancevia
Temporal range: Wuchiapingian, 260–254Ma
Inostrancevia alexandri.JPG
Mounted skeleton of an Inostrancevia alexandri
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Synapsida
Order: Therapsida
Family: Gorgonopsidae
Genus: Inostrancevia
Amalitsky, 1922
Type species
Inostrancevia alexandri
Amalitsky, 1922
Species
  • I. alexandri Amalitsky 1922
  • I. latifrons Pravoslavlev, 1927
  • I. uralensis Tatarinov, 1984
Synonyms
  • Amalitzkia Pravoslavlev, 1927

Inostrancevia is an extinct genus of carnivorous therapsids, containing the largest members of the family Gorgonopsidae, predators characterized by long, saber-tooth-like canines. The various species inhabited Northern Russia during the Upper Tatarian (Vyatskian),[1] a Russian regional stage equivalent to the Wuchiapingian stage of the Late Permian period,[2] dating from approximately 260 to 254 mya. It is known from several skulls and two almost complete skeletons.[3]

Description[edit]

An I. alexandri attacking a Scutosaurus karpinski

The species in Inostrancevia were the largest gorgonopsids known, known individuals have total body lengths reaching up to 3.5 m (11 ft 6 in) and long, narrow skulls up to 60 cm (24 in) long. Like several other gorgonopsids, Inostrancevia was characterized by strongly developed canine teeth, with those of the upper jaw up to 15 cm (5.9 in) long, the root corresponding to half its length. Their bodies were slender, with rather short legs.[1] Inostrancevia shared its habitat with Scutosaurus which it likely preyed upon.[1]

Etymology[edit]

Inostrancevia was named by the Russian paleontologist Vladimir P. Amalitsky[4] in honour of the Russian geologist Aleksandr Inostrantsev.[5]

Discovery[edit]

Holotype skeleton

The first fossils were found in the Sokolki Assemblage in the Oblast of Arkhangelsk[1] as part of the Northern Dvina River excavations lead by Amalitsky during the end of the 19th century. Two nearly complete skeletons were found alongside several other skeletal remains, one of which was mounted and exhibited in Saint Petersburg in 1900 with the other following a few years later. Proper descriptions of the findings were published posthumously in 1922.[3][4]

Classification[edit]

Below is a cladogram from the phylogenetic analysis of Gebauer (2007):[6]

Gorgonopsia 

Aloposaurus




Cyonosaurus




Aelurosaurus


Gorgonopsidae

Scylacognathus




Eoarctops



Gorgonops




Njalila




Lycaenops




Arctognathus




Inostrancevia


Rubidgeinae

Aelurognathus




Rubidgea




Sycosaurus



Clelandina














References[edit]

  1. ^ a b c d Ivakhnenko, M. F. (2001). "Tetrapods from the East European Placket—Late Paleozoic Natural Territorial Complex.". Proceedings of the Paleontological Institute of the Russian Academy of Sciences (in Russian) 283: 1–200 [103]. 
  2. ^ Kukhtinov, D. A.; Lozovsky, V. R.; Afonin, S. A.; Voronkova, E. A. (2008). "Non-marine ostracods of the Permian-Triassic transition from sections of the East European platform". Boll.Soc.Geol.It. (Ital.J.Geosci.) 127 (3). 
  3. ^ a b Pravoslavlev, P. A. (1927). "Gorgonopsidae from the North Dvinsky excavations of V. P. Amalitsky.". Academy of Sciences of the Union of Soviet Socialist Republics (Leningrad): 170. 
  4. ^ a b Amalitsky, V. P. (1922). "Diagnoses of the new forms of vertebrates and plants from the upper Permian of North Dvina.". Bulletin of the Russian Academy of Sciences. (Saint Petersburg) 16 (6): 329–340. 
  5. ^ "Inostrancevia". Paleofile. Retrieved 4 January 2014. 
  6. ^ Gebauer, E.V.I. (2007). Phylogeny and evolution of the Gorgonopsia with a special reference to the skull and skeleton of GPIT/RE/7113 ('Aelurognathus?' parringtoni) (Ph.D. thesis). Tübingen: Eberhard-Karls Universität Tübingen. pp. 1–316. 

External links[edit]