Jonkeria

Taxobox
name = "Jonkeria"
fossil_range = Middle Permian

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image_width = 250px
image_caption = life restoration of "Jonkeria truculenta"
regnum = Animalia
phylum = Chordata
subphylum = Vertebrata
classis = Synapsida
ordo = Therapsida
subordo = Dinocephalia
infraordo = Tapinocephalia
familia = Titanosuchidae
genus = "Jonkeria"
genus_authority = Van Hoepen, 1916
subdivision_ranks = Species
subdivision = "J. truculenta" "J. boonstrai" "J. haughtoni" "J. ingens" "J. koupensis" "J. parva" "J. rossouwi" "J. vanderbyli"

"Jonkeria" was a very large herbivorous (although sometimes thought to be carnivorous - e.g. Colbert 1969 p.136) dinocephalian, from the Tapinocephalus Assemblage Zone, Lower Beaufort Group, of the South African Karroo. The overall length was three and a half meters or more (up to 4 or 5 meters), the skull about 55 cm long. The skull is nearly twice as long as wide, and the snout is elongated and provided with sharp incisors and large canines. The cheek teeth were rather small.

The body is robustly built, and the limbs stout. According to Boonstra 1969 p.38, Jonkeria cannot be distinguished from its relative "Titanosuchus" on cranial grounds, but only in limb length; "Jonkeria" having short and squat limbs, and "Titanosuchus" long ones.

About a dozen species have been named, including the type species, "J. truculenta". At least some of the other species were synonymised by Boonstra 1969. There has been no recent review of the genus.

References

* Boonstra, L. D. 1969, "The Fauna of the Tapincephalus Zone (Beaufort Beds of the Karoo)," Ann. S. Afr. Mus. 56 (1) 1-73, pp. 35-38
* Colbert, E. H., (1969), "Evolution of the Vertebrates", John Wiley & Sons Inc (2nd ed.)
*von Zittel, K.A (1932), "Textbook of Paleontology", C.R. Eastman (transl. and ed), 2nd edition, Macmillan & Co. vol.2, p.255

Links

* [http://www.palaeos.com/Vertebrates/Units/400Therapsida/600.html#Jonkeria Jonkeria] - Palaeos
* [http://csotonyi.com/AnnessJonkeria.html Jonkeria] - life reconstruction