Open Paleo

Priconodon

Marsh, 1888 pry-KON-oh-don Disputed

From Greek prion (saw), konos (cone), and odon (tooth); meaning "saw cone tooth".

121.4–113.2 million years ago Aptian, Early Cretaceous
Early Cretaceous stages

Priconodon is an extinct genus of ankylosaurian dinosaur (perhaps nodosaurid), mainly known from its large teeth. Its remains have been found in the Early Cretaceous (Aptian-Albian age) Arundel Formation of Muirkirk, Prince George's County, Maryland, USA, and possibly the Potomac Group, also located in Maryland. As an ankylosaur, Priconodon would have been a large armored quadrupedal herbivore, though no size estimation has been done due to the scarcity of described remains.

Under dispute

The validity of Priconodon crassus is contested. It is known essentially only from teeth, with a referred tibia, from the Arundel Formation of Maryland. Carpenter and Kirkland (1998) treated it as a valid taxon and gave a revised tooth-based diagnosis, while accepting its nodosaurid placement only tentatively and allowing that it might not be an ankylosaur; West and Tibert (2004) argued from a morphometric analysis that it is a distinct taxon, and Coombs (1978) had earlier treated it as valid; other workers have instead listed it as a nomen dubium without comment (Olshevsky, 1991; Ford, 2000; Vickaryous and colleagues, 2004). Arbour and Currie (2015) summarized this disagreement. It is retained at Ankylosauria incertae sedis pending resolution.

Diagnosis

  1. Tooth with narrow neck, swollen base, and flattened crown
  2. Serrated edges meeting above at sharp angle rather than forming wide curve at apex

Species

Priconodon crassus Marsh, 1888 Disputed

Type species

From Latin 'crassus' meaning 'dense' or 'thick'.

Holotype
USNM 2135 , National Museum of Natural History, Smithsonian Institution
Material
A worn tooth.
Horizon
Arundel Formation, Aptian, Early Cretaceous , 121.4–113.2 million years ago
Locality
Muirkirk, Maryland, United States

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 s3-35(205): 89-94. American Journal of Science (AJS). doi:10.2475/ajs.s3-35.205.89

    Erected Priconodon crassus on a tooth, giving the provenance only as the Potomac formation of Prince George County, Maryland, without a closer locality.

    marsh1888a
  2. Olshevsky, G. (1991). A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings 2: 1-196.

    Listed Priconodon crassus as a nomen dubium.

    olshevsky1991a
  3. Carpenter, K.; Kirkland, J. I. (1998). Review of Lower and Middle Cretaceous ankylosaurs from North America. Lower and Middle Cretaceous Terrestrial Ecosystems (Lucas, S. G.; Kirkland, J. I.; Estep, J. W., eds.) 14: 249-270.

    Treated Priconodon crassus as valid and gave a revised, tooth-based diagnosis; accepted a nodosaurid placement only tentatively, allowing that it might not be an ankylosaur.

    carpenter1998c
  4. Ford, T. L. (2000). A review of ankylosaur osteoderms from New Mexico and a preliminary review of ankylosaur armor. Dinosaurs of New Mexico 17: 157-176.

    Listed Priconodon crassus as a nomen dubium.

    ford2000a
  5. Vickaryous, M. K.; Maryańska, T.; Weishampel, D. B. (2004). Ankylosauria. The Dinosauria, Second Edition (Weishampel, D. B.; Dodson, P.; Osmólska, H., eds.) 363-392. University of California Press, Berkeley.

    Listed Priconodon crassus among nomina dubia, on teeth and a tibia, without discussion.

    vickaryous2004a
  6. West, A.; Tibert, N. (2004). Quantitative analysis for the type material of Priconodon crassus: a distinct taxon from the Arundel Formation in southern Maryland. Geological Society of America Abstracts with Programs 36: 423.

    Argued from a morphometric analysis of the type material that Priconodon crassus is a distinct taxon.

    west2004a
  7. Arbour, V. M.; Currie, P. J. (2015). Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs. Journal of Systematic Palaeontology 14(5): 385-444. Informa UK Limited. doi:10.1080/14772019.2015.1059985

    Summarized the disagreement over the validity of Priconodon crassus.

    arbour2015a
  8. Coombs, W. P. Jr. (1978). The families of the ornithischian dinosaur order Ankylosauria. Palaeontology 21(1): 143-170. coombs1978a