Priconodon Temporal range: Early Cretaceous, | |
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Priconodon tooth in multiple views | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | †Ornithischia |
Clade: | †Thyreophora |
Clade: | †Ankylosauria |
Family: | †Nodosauridae |
Genus: | †Priconodon |
Species: | †P. crassus |
Binomial name | |
†Priconodon crassus Marsh, 1888 |
Priconodon (meaning "saw cone tooth"[1]) is an extinct genus of ankylosaurian dinosaur (perhaps nodosaurid), mainly 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, USA and 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.
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.[2] It was not identified as an ankylosaurian until Walter Coombs assigned it to Nodosauridae in 1978.[3]
In 1998 Kenneth Carpenter and James Kirkland, in a review of North American Lower Cretaceous ankylosaurs, considered it tentatively valid as an unusually large nodosaurid, larger than all those described before.[4] Carpenter (2001) retained it as a valid nodosaurid, but did not employ it in his phylogenetic analysis.[5] Vickaryous et al. (2004), in a review of armored dinosaurs, considered it to be dubious without comment.[6] West and Tibert, however, followed this with a preliminary account of a morphometric study that found it to be a unique genus.[7]
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.[4] In 2018, three new ankylosaur teeth described from the Potomac Formation were assigned to Priconodon crassus based on their similarity to the holotype.[8] In 2023, large ankylosaur fossils (including vertebrae and a tail club) were announced to be found at Dinosaur Park by John-Paul Hodnett,[9][10] which may potentially represent additional specimens of Priconodon.[11]