The type species, "A. remotus", is known from a partial skull and three foot bones. They were got from Mongolian sediments which were deposited in a humid floodplain about 70 million years ago. A second species, "A. altai", known from a much more complete skeleton, was named and described in 2009. Its relationships to other tyrannosaurid genera are unclear. Some evidence suggests that "Alioramus" is closely related to the contemporary species "Tarbosaurus bataar".