Troodon formosus, Leidy, 1856

Leidy, J., 1856, Notice of remains of extinct reptiles and fishes, discovered by Dr. FV Hayden in the Bad Lands of the Judith River, Nebraska Territory., Proceedings of the Academy of Natural Sciences of Philadelphia 8, No. 7, pp. 72-73 : 72

3. Troodon formosus , Leidy.

The genus and species are founded on a single specimen of a tooth of a lacertian, discovered by Dr. Hayden.

The specimen consists of a compressed, curved, conical crown with trenchant edges. The outer side is more convex than the inner, which is worn off towards the apex from friction of the opposing tooth. The trenchant edges are coarsely denticulated; the denticulations themselves being compressed conical, with trenchant edges, and are bent in such a manner that their apices are directed towards the summit of the crown. The base of the tooth is hollow, and is 2 lines wide and 1 1/4 lines transversely; and the length of the specimen is 3 lines.