Biology:Kangnasaurus
Kangnasaurus (meaning "Farm Kangnas lizard") is a genus of elasmarian ornithopod dinosaur found in Late Cretaceous rocks of South Africa. It is known from a tooth and possibly some postcranial remains dating between the middle-Campanian to Maastrichtian Kalahari Deposits Formation.[1]
Discovery and naming
Kangnasaurus was named in 1915 by Sidney H. Haughton. The type species is Kangnasaurus coetzeei. The generic name refers to the Kangnas farm; the specific name to the farmer, Coetzee. Kangnasaurus is based on holotype SAM 2732, a tooth found at a depth of 34 metres in a well at Farm Kangnas, in the Orange River valley of northern Cape Province, South Africa.[2] The age of these rocks, conglomerates in an ancient crater lake, was once suggested to date to the Early Cretaceous (probably early-Aptian) due to the original phylogenetic position of the taxa as a dryosaurid.[3] But a Late Cretaceous age between the Campanian and Maastrichtian is more likely due to sedimentological analyses.[4] Haughton thought SAM 2732 was a tooth from the upper jaw, but Michael Cooper reidentified it as a lower jaw tooth in 1985.[5] This had implications for its classification: Haughton thought the tooth was that of an iguanodontid,[2] while Cooper identified it as from an animal more like Dryosaurus, a more basal ornithopod.[5]
Haughton described several other fossils as possibly belonging to Kangnasaurus. These include five partial thigh bones, a partial thigh bone and shin bone, a partial metatarsal, a partial shin and foot, vertebrae, and unidentified bones. Some of the bones apparently came from other deposits, and Haughton was not certain that they all belonged to his new genus.[2] Cooper was also not certain, but described the other specimens as if they did belong to Kangnasaurus.[5] Like other basal iguanodontians, it would have been a bipedal herbivore.[6]
Classification
Kangnasaurus was originally regarded as dubious,[7][6] although a 2007 review of dryosaurids by Ruiz-Omeñaca and colleagues retained it as potentially valid, differing from other dryosaurids by details of the thigh bone.[3]
The differences in interpretation between Haughton and Cooper regarding the placement of the tooth had implications for the taxon's classification: Haughton thought the tooth was indicative that of an iguanodontid when interpreted as a maxillary position,[2] while Cooper classified it as coming from an animal more like Dryosaurus based on his assignment of the tooth to the dentary.[5] However, more recent studies have separately uncovered a position nested within the elasmarian group.[8][9][10]
References
- ↑ "Table 19.1," in Weishampel, et al. (2004). Page 417.
- ↑ 2.0 2.1 2.2 2.3 2.4 Haughton, Sidney H. (1915). "On some dinosaur remains from Bushmanland". Transactions of the Royal Society of South Africa 5 (1): 259–264. doi:10.1080/00359191509519723. Bibcode: 1915TRSSA...5..259H. https://zenodo.org/record/1430389.
- ↑ 3.0 3.1 Ruiz-Omeñaca, José Ignacio; Pereda Suberbiola, Xavier; Galton, Peter M. (2007). "Callovosaurus leedsi, the earliest dryosaurid dinosaur (Ornithischia: Euornithopoda) from the Middle Jurassic of England". in Carpenter Kenneth. Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. Bloomington and Indianapolis: Indiana University Press. pp. 3–16. ISBN 978-0-253-34817-3.
- ↑ "Iyuku raathi, a new iguanodontian dinosaur from the Early Cretaceous Kirkwood Formation, South Africa". The Anatomical Record 306 (7): 1762–1803. 2022. doi:10.1002/ar.25038. PMID 35860957.
- ↑ 5.0 5.1 5.2 5.3 Cooper, Michael R. (1985). "A revision of the ornithischian dinosaur Kangnasaurus coetzeei Haughton, with a classification of the Ornithischia". Annals of the South African Museum 95 (8): 281–317.
- ↑ 6.0 6.1 Norman, David B. (2004). "Basal Iguanodontia". in Weishampel, D.B.. The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 413–437. ISBN 0-520-24209-2.
- ↑ Sues, Hans-Dieter; Norman, David B. (1990). "Hypsilophodontidae, Tenontosaurus, Dryosauridae". in Weishampel, David B.. The Dinosauria (1st ed.). Berkeley: University of California Press. pp. 498–509. ISBN 0-520-06727-4.
- ↑ Rozadilla, Sebastián; Agnolín, Federico Lisandro; Novas, Fernando Emilio (2019-12-17). "Osteology of the Patagonian ornithopod Talenkauen santacrucensis (Dinosauria, Ornithischia)". Journal of Systematic Palaeontology 17 (24): 2043–2089. doi:10.1080/14772019.2019.1582562. ISSN 1477-2019. Bibcode: 2019JSPal..17.2043R. https://www.researchgate.net/publication/332843404.
- ↑ "A new phylogeny of cerapodan dinosaurs". Historical Biology 33 (10): 2335–2355. 2020. doi:10.1080/08912963.2020.1793979.
- ↑ Fonseca, A.O.; Reid, I.J.; Venner, A.; Duncan, R.J.; Garcia, M.S.; Müller, R.T. (2024). "A comprehensive phylogenetic analysis on early ornithischian evolution". Journal of Systematic Palaeontology 22 (1). doi:10.1080/14772019.2024.2346577.
Wikidata ☰ Q633747 entry
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