Ankylosaurus tooth

Taxonomy

Ankylosaurus

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Ornithischia
Family: Ankylosauridae
Genus: Ankylosaurus
Species: Ankylosaurus magniventris
Author Citation Brown, 1908

Geological Time Scale

Eon: Phanerozoic
Era: Mesozoic
Period: Cretaceous
Sub Period: None
Epoch: Late
International Age: Maastrichtian

Stratigraphy

Hell Creek Formation

Provenance

Collector: K. Fitch
Acquired by: Purchase/Trade

Dimensions

Height: 11 mm

Location

Garfield County
Montana
United States

• ankylosauria
• ankylosauridae
• ankylosaurus
• ankylosaurus magniventris
• c(hc)am1
• hell creek
• hell creek formation

Comments

Identification

Teeth of Nodosaurids are often confused for those of their rarer relatives, the Ankylosaurids, namely the archetypical Ankylosaurian, Ankylosaurus. (Most) teeth of Ankylosaurus are taller than they are wide, are generally conical in shape with one side flatter than the other, have large denticles on the anterior and posterior edges (6-8 anterior, 5-7 posterior), and have swollen/bulbous bases. Tooth wear is normally on the crown face, compared to wear on the tip (apex) as in Nodosaurids.^1,2 

Comments

This tooth is partially rooted; the root is cylindrical and hollow. There is a wear facet on one side, offset from the center, with grooves roughly perpendicular to the apicobasal axis (suggestive of the mastication motion). This tooth was found in the same county as the holotype of this species.

References

1. Carpenter, K. "Redescription of Ankylosaurus magniventris Brown 1908 (Ankylosauridae) from the Upper Cretaceous of the Western Interior of North America." Canadian Journal of Earth Sciences (2004), 41(8): 961-986. https://doi.org/10.1139/e04-043 

2. Carpenter, K. "Baby dinosaurs from the Lance and Hell Creek formations and a description of a new theropod." Contributions to Geology (1982), 20: 123–134.