Priconodon

Priconodon
Temporal range: Early Cretaceous, 113Ma
Priconodon tooth in multiple views
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Superorder: Dinosauria
Order: Ornithischia
Suborder: Thyreophora
Infraorder: Ankylosauria
Family: ?Nodosauridae
Genus: Priconodon
Species: P. crassus
Binomial name
Priconodon crassus
Marsh, 1888

Priconodon is an extinct genus of dinosaur (perhaps nodosaurid), known from its large teeth. Its remains have been found in the Aptian-Albian age Lower Cretaceous Arundel Formation of Muirkirk, Prince George's County, Maryland.

History

O. C. Marsh named the genus for USNM 2135, a large worn tooth from what was then called the Potomac Formation. As ankylosaurians were by and large unknown at the time, he compared it to Diracodon (=Stegosaurus) teeth.[1] It wasn't identified as an ankylosaurian until Walter Coombs assigned it to Nodosauridae in 1978.[2]

As a tooth genus, it has not attracted much attention. Recently, though, Kenneth Carpenter and James Kirkland (1998), in a review of North American Lower Cretaceous ankylosaurs, considered it tentatively valid as an unusually large nodosaurid, larger than all those described before.[3] Carpenter (2001) retained it as a valid nodosaurid, but did not employ it in his phylogenetic analysis.[4] Vickaryous et al. (2004), in a review of armored dinosaurs, considered it to be dubious without comment.[5] West and Tibert, however, followed this with a preliminary account of a morphometric study that found it to be a unique genus.[6]

Material

Tooth

Carpenter and Kirkland (1998) listed 12 additional teeth from the same area as the holotype tooth, and tentatively added a robust tibia (USNM 9154) to the genus. They found the lack of armor found in the Arundel to be peculiar, but noted that fossils are rare in that formation anyway.[3]

Paleobiology

As a nodosaurid, Priconodon would have been a slow, armored, quadrupedal herbivore.[5] It would have been a large nodosaurid, but since only teeth are definitely known for the genus, size estimation has not been done.

References

  1. Marsh, O.C. (1888). Notice of a new genus of Sauropoda and other new dinosaurs from the Potomac Formation. American Journal of Science 135:89-94.
  2. Coombs, Jr., W.P. (1978). The families of the ornithischian dinosaur order Ankylosauria. Palaeontology 21(1):143-170.
  3. 3.0 3.1 Carpenter, K., and Kirkland, J.I. (1998). Review of Lower and middle Cretaceous ankylosaurs from North America. In: Lucas, S.G., Kirkland, J.I., and Estep, J.W. (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bulletin 14:249-270.
  4. 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
  5. 5.0 5.1 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
  6. West, A. and Tibert, N. (2004). Quantitative analysis for the type material of Priconodon crassus: a distinct taxon from the Arundel Formation in souther Maryland. Geological Society of America Abstracts with Programs, 36(5):423.