and has been the subject of numerous conflicting synonymies with similar theropod specimens.

The Troodon tooth was originally classified as a "lacertilian" (lizard) by Leidy, but reassigned as a megalosaurid dinosaur by Franz Nopcsa von Felso-Szilvás in 1901 (Megalosauridae having historically been a wastebin taxon for most carnivorous dinosaurs). In 1924, Gilmore suggested