1.10" Nanotyrannus Tooth - Tooth Draw Quarry

This is a 1.10" long Tyrannosaurid tooth of the genus Nanotyrannus lancensis tooth from the Hell Creek Formation of South Dakota. Most of the enamel is in good shape and the serrations are visible. There has been several repairs and minor gap fills in the tooth because it was found in pieces and put back together.

Tyrannosaurus rex (T-Rex) are really the same species, with Nanotyrannus representing juveniles. Recent finds that are soon to be published should put this debate to rest, definitively proving that Nanotyrannus is in fact a separate genus and valid genus. Nano teeth tend to be much more finely serrated, and much thinner/blade like t-rex teeth, in addition to being smaller.

This tooth was found at a private ranch in Butte County, South Dakota earlier this summer. It comes from a quarry known as the "Tooth Draw Quarry" that has produced many high quality dinosaur teeth over the past several decades. In the Late Cretaceous some 65 million years ago, this quarry was located in a sub-tropical floodplain that would have been similar to modern day coastal Louisiana. It consists of 2 meters of alternating sandstone and gravel, representing a river channel lag deposit. It contains many isolated dinosaur teeth including T-Rex, Nanotyrannus, Raptors and Triceratops, but teeth of this high quality are rare finds.

The last two photos show the collecting location.