.85" Partial, Juvenile Tyrannosaur Premaxillary Tooth - Montana

This is a .85" long, partial premaxillary tooth from the juvenile Tyrannosaur. It comes from the Judith River Formation of Montana which is about 5 million years older than the Hell Creek Formation where T-Rex is found. The premax teeth of juvenile Tyrannosaurs have a very distinctive shape, but originally caused them to be labeled as teeth from a different dinosaur.

There are three described Tyrannosaurs from the Two Medicine Formation (Judith River Group), Albertosaurus, Gorgosaurus and Daspletosaurus. Research done on teeth from these three Tyrannosaurs has concluded that isolated teeth are statistically impossible to assign to a specific genre because they are so similar.

Morphometry of the teeth of western North American tyrannosaurids and its applicability to quantitative classification