Priodontognathus

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Priodontognathus
Fossil range: ?Upper Jurassic
Conservation status
Fossil
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Superorder: Dinosauria
Order: Ornithischia
Suborder: Thyreophora
Infraorder: Ankylosauria
Family: uncertain
Genus: Priodontognathus
Seeley, 1875
Species: P. phillipsii
(Seeley, 1869 [originally Iguanodon])
Binomial name
Priodontognathus phillipsii
Seeley, 1875

Priodontognathus (meaning "saw tooth jaw") was a genus of ankylosaurian dinosaur possibly from the Oxfordian-age Upper Jurassic Lower Calcareous Grit of Yorkshire, England. It is a dubious genus based on a maxilla, and has been erroneously mixed up with iguanodonts and stegosaurs.

Contents

[edit] History and Taxonomy

English paleontologist Harry Seeley, who described the genus, first mentioned the holotype maxilla (SMC B53408) in 1869.[1] The locality was unknown, but believed to be somewhere near the coast of Yorkshire.[2] He initially thought that it was referable to Iguanodon, and named it I. phillipsii. By 1875, he'd recognized that it was different, and so gave it the generic name Priodontognathus, in recognition of the form of its teeth.[3]

Because armored dinosaurs were very poorly known at the time, he had little to compare it to, and in light of this it is not too surprising that he later (1893) had it mixed up with the stegosaurian Omosaurus (now Dacentrurus) as Omosaurus phillipsii.[2] At this time, he confusingly named a species Omosaurus phillipsi based on a femur (YM 498), and seems to have tentatively assigned the species to Priodontognathus despite their having the same species name (see at the bottom), and despite the two species being based on non-comparable material.[2]

After this time, it was generally considered to be a stegosaurid,[4][5] although at least one author recognized that it was not, and assigned it to "Acanthopholididae", which we would recognize as Nodosauridae.[6] Alfred Sherwood Romer also recognized that it was an ankylosaurian, although he synonymized it with Hylaeosaurus.[7]

Peter Galton reassessed the genus in 1980 and established that it was a distinct genus, which he compared to Priconodon and Sauropelta and assigned to Nodosauridae.[8] While his assessment of it as a type of ankylosaurian has been accepted, his belief that it was valid was not, and it has been usually considered a dubious genus of uncertain ankylosaurian affinities since then.[9][10][11][12]

[edit] Paleobiology

As an ankylosaurian, Priodontognathus would have been a slow quadrupedal herbivore, built low to the ground, and possessing armor as a protective feature against theropods and other carnivores.[12]

[edit] "Omosaurus" phillipsii

As mentioned, Seeley named a femur Omosaurus phillipsii in 1893, which has become confused with this animal, due to being discussed in the same article (and considered to possibly be the same genus), and due to them having the same species name. Omosaurus phillipsii, now known as "Dacentrurus" phillipsii or "Omosaurus" phillipsii (depending on how an author denotes dubious species), is a dubious species of stegosaurian from the Malton Oolite Member of the Coralline Oolite Formation, Slingsby, North Yorkshire.[2] Galton (1983) found it to have no diagnostic features, and that its major significance was of being the only record then known of Oxfordian stegosaurians.[13] The femur, which is in three pieces, is that of a juvenile.[13]

[edit] Miscellany

The double "i" at the end of the species name for both Priodontognathus and "Omosaurus" phillipsii is an old formulation and is today not done. The extra "i" has not been formally removed, but authors sometimes leave it off. For that matter, as mentioned above regarding the name of "Omosaurus" phillipsi, Priodontognathus will sometimes be referred to as "Iguanodon" phillipsii.[9][11][12]

[edit] References

  1. ^ Seeley, H.G. (1869). Index to the fossil remains of Aves, Ornithosauria, and Reptilia from the Secondary Strata. Cambridge University Press:Cambridge, 143 p.
  2. ^ a b c d Seeley, H.G. (1893). On Omosaurus phillipsii. Annual Report, Yorkshire Philosophical Society, 1892. 52-57.
  3. ^ Seeley, H.G. (1875). On the maxillary bone of a new dinosaur (Priodontognathus phillipsii), contained in the Woodwardian Museum of the University of Cambridge. Quarterly Journal of the Geological Society of London 31:439-443.
  4. ^ von Huene, F. (1909). Skizze zu einer Systematik und Stammesgeschichte der Dinosaurier. Centralblatt für Mineralogie, Geologie und Paläontologie 1909:12-22. [German]
  5. ^ von Zittel, K.A.. (1911). Grundzüge der Paläontologie (Paläozoologie). II. Abteilung. Vertebrata. Druck und Verlag von R. Oldenbourg:München, 1-598. [German]
  6. ^ Nopcsa, B.F. (1902). Notizen über cretacische Dinosaurier. Sitzungsberichte der Mathematisch-Naturwissenschaftlichen Classe der Kaiserlichen Akademie der Wissenschaften 111(1):93-114. [German]
  7. ^ Romer, A.S. (1956). Osteology of the Reptiles. University of Chicago Press:Chicago, 1-772. ISBN 0-89464985-X
  8. ^ Galton, P.M. 1980. Priodontognathus phillipsii (Seeley), an ankylosaurian dinosaur from the Upper Jurassic (or possibly Lower Cretaceous) of England. Neues Jahrbuch für Geologie und Paläontologie Monatshefte 1980(8):477-489.
  9. ^ a b Coombs, Jr., W.P., and Maryańska, T. (1990). Ankylosauria. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (first edition). University of California Press:Berkeley, 456-483. ISBN 0-520-06727-4
  10. ^ Ford, T.L. (2000). A review of ankylosaur osteoderms from New Mexico and a preliminary review of ankylosaur armor. In: Lucas, S.G., and Heckert, A.B. (eds.). Dinosaurs of New Mexico. New Mexico Museum of Natural History and Science Bulletin 17:157-176.
  11. ^ a b Carpenter, K. (2001). Phylogenetic analysis of the Ankylosauria. In: Carpenter, K. (ed.). The Armored Dinosaurs. Indiana University Press:Bloomington, 455-483. ISBN 0-253-33964-2
  12. ^ a b c Vickaryous, M.K., Maryańska, T., and Weishampel, D.B. (2004). Ankylosauria. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (second edition). University of California Press:Berkeley, 363-392. ISBN 0-520-24209-2
  13. ^ a b A juvenile stegosaurian dinosaur, Omosaurus phillipsii Seeley from the Oxfordian (Upper Jurassic) of England. Géobios 16:95-101.

[edit] External links

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