Paranthodon

Holozoa

Paranthodon
Temporal range: Early Cretaceous, 140 Ma
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Dinosauria
Order: Ornithischia
Suborder: Stegosauria
Family: Huayangosauridae
Genus: Paranthodon
Broom
Species: P. africanus
Binomial name
Paranthodon africanus
Broom

Paranthodon (Meaning "Beside Anthodon") was a dinosaur from the early Cretaceous. It lived in what is now South Africa. It is classified as a stegosaur. It has a long and confusing history. The type species, Paranthodon africanus, comes from a partial skull first described as Palaeoscincus africanus in 1912. It was renamed as Paranthodon in 1929 by the famed Franz Nopcsa. It owes its name to the fact that its jaw was found near the fossils of a Permian pareiasaur named Anthodon.

In 1845 amateur geologists William Guybon Atherstone and Andrew Geddes Bain near Dassieklip, Cape Province, in the valley of the Bushmans River found a number of fossils. Bain in 1849 and 1853 sent some to the British paleontologist Richard Owen for identification. Among them was the upper jaw of what Bain thought was a dinosaur that he informally had indicated as the "Cape Iguanodon"; the site likewise was named "Iguanodonhoek". In 1857 Atherstone published about the find,[1] but in 1871 lamented that it as yet had received no attention in London. Only in 1876 Owen named a series of specimens as Anthodon serrarius.[2] Anthodon means "flower tooth".

In 1909 the South-African paleontologist Robert Broom visited the collection of the British Museum of Natural History. He concluded that Owen had mixed the fossils of two entirely different species: those of a member of the Pareiasauria and a dinosaur jaw. Broom kept the name Anthodon for the pareiasaur and identified the dinosaur fossil as belonging to the genus Paleoscincus, naming in 1910/1912 the new species Paleoscincus africanus.[3]

In 1929 Baron Franz Nopcsa also studied the specimen. Unaware of Broom's publication he basically drew the same conclusions but also named a new genus coining for the dinosaur the name Paranthodon Oweni.[4] The generic name means "near" or "besides" (para in Greek) Anthodon. The specific name honours Owen. In his publication Nopcsa by mistake also used the spelling variant Paranthodon Owenii. By present conventions the name should be written as Paranthodon oweni.

Only in 1978 Walter Coombs correctly combined both names into a Paranthodon africanus.[5]

The holotype, BMNH 47338, was found in a layer of the Kirkwood Formation dating from the Berriasian-Valanginian. It consists of the back of the snout, containing the maxilla with teeth, the posterior caudodorsal ramus of the premaxilla and part of the nasals. The snout is elongated but not extremely so and convex on top; the back of the premaxilla is long and broad; the external nares are large. The teeth have a prominent primary ridge.

Paleoscincus is a ankylosaur genus. Nopcsa however, thought Paranthodon was a member of the Stegosauridae, related to Stegosaurus and Kentrosaurus. After 1929 most scientists nevertheless tended to classify Paranthodon as an ankylosaur. Only in 1981 Peter Galton established it was indeed a stegosaurid.[6] If so, it would be about five metres long and be the second stegosaur discovered, after Regnosaurus, besides being the first dinosaur found in South-Africa.[7] According to a recent analysis it would be closely related to Tuojiangosaurus, Loricatosaurus and Stegosaurus.[8]

Notes

  1. ^ Atherstone, W.G. (1857). "Geology of Uitenhage". The Eastern Province Monthly Magazine 1 (10): 518–532. 
  2. ^ Owen, R., 1876, Descriptive and illustrative catalogue of the fossil Reptilia of South Africa in the collection of the British Museum, 'Trustees of the British Museum, London, p.87
  3. ^ Broom, R. (1912). "Observations on some specimens of South African fossil reptiles preserved in the British Museum". Transactions of the Royal Society of South Africa 2: 19–25. doi:10.1080/00359191009519357. 
  4. ^ Nopsca, F. (1929). "Dinosaurierreste aus Siebenburgen V. Geologica Hungarica. Series Palaeontologica". Fasciculus 4: 1–76. 
  5. ^ Coombs W.P. Jr (1978). "The Families of the Ornithischian Dinosaur Order Ankylosauria". Palaeontology 21: 143–170. http://palaeontology.palass-pubs.org/pdf/Vol%2021/Pages%20143-170.pdf. 
  6. ^ Galton P.M. (1981). "Craterosaurus pottonensis Seeley, a stegosaurian dinosaur from the Lower Cretaceous of England, and a review of Cretaceous stegosaurs". Neues Jahrbuch für Geologie und Paläontologie 161 (1): 28–46. 
  7. ^ De Klerk, W.J., Raath, M. and Hiller, N., 1992, "The first South African dinosaur: A palaeontological site of historical significance", 7th Biennial Conference of the Palaeontology Society of S.A., University of the Witwatersrand. Abstract Vol. p.48
  8. ^ Maidment, S. C. R.; Norman, D. B.; Barrett, P. M.; Upchurch, P. (2008). "Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia)". Journal of Systematic Palaeontology 6 (4): 367–407. doi:10.1017/S1477201908002459. 

References