In 1946, Charles W. Gilmore was the first to observe that certain anatomical features may link "Dryptosaurus" with coeval Late Cretaceous tyrannosaurids, "Albertosaurus" and "Tyrannosaurus". This observation was also supported by the work of Baird and Horner (1979), but did not have wide acceptance until a new discovery was made in 2005. "Dryptosaurus" was the only large carnivore known in eastern North America until the discovery of the basal tyrannosauroid "Appalachiosaurus" in 2005. "Appalachiosaurus" which is known from more complete remains, is similar to "Dryptosaurus" in both body size and morphology. This discovery made it clear that "Dryptosaurus" was a primitive tyrannosauroid. Detailed phylogenetic analysis by Brusatte et al. (2011) confirmed the tyrannosauroid affinities of "Dryptosaurus" and assigned it as an “intermediate” tyrannosauroid that is more derived than basal taxa such as "Guanlong" and "Dilong", but more primitive than members of the more derived Tyrannosauridae.