Jonkeria Temporal range: Capitanian, | |
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Jonkeria ingens skull, Amer. Mus. No. 5608 | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Synapsida |
Clade: | Therapsida |
Suborder: | †Dinocephalia |
Family: | †Titanosuchidae |
Genus: | †Jonkeria Van Hoepen, 1916 |
Type species | |
Jonkeria truculenta | |
Species | |
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Synonyms | |
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Jonkeria is an extinct genus of dinocephalians. Species were very large and omnivorous (although there is some dispute to this, e.g. Colbert 1969 p. 136), from the Tapinocephalus Assemblage Zone, Lower Beaufort Group, of the South African Karoo.
Description
The overall length was 3.5 metres (11.5 ft) or more (up to 4 or 5 metres (13.1 or 16.4 ft)), 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 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.
Evidence of femoral osteomyelitis has been described in a fossilised specimen of J. parva. The authors attributed the cause of the pathology, characterised by bony spicules growing perpendicular to nonpathological fibrolamellar bone tissue, to a bacterial infection resulting from an attack by a predator, as evidenced by puncture marks on the femur.[1]
Classification
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.
See also
References
- ↑ Shelton, Christen D.; Chinsamy, Anusuya; Rothschild, Bruce M. (25 December 2017). "Osteomyelitis in a 265-million-year-old titanosuchid (Dinocephalia, Therapsida)". Historical Biology. 31 (8): 1093–1096. doi:10.1080/08912963.2017.1419348. Retrieved 20 October 2022.
- 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