In 1994, Holtz grouped tyrannosauroids with elmisaurids, ornithomimosaurs and troodonts into a coelurosaurian clade called Arctometatarsalia based on a common ankle structure where the second and fourth metatarsals meet near the tarsal bones, covering the third metatarsal when viewed from the front. Basal tyrannosauroids like "Dilong", however, were found with non-arctometatarsalian ankles, indicating that this feature evolved convergently. Arctometatarsalia has been dismantled and is no longer used by most paleontologists, with tyrannosauroids usually considered to be basal coelurosaurs outside Maniraptoriformes. One recent analysis found the family Coeluridae, including the Late Jurassic North American genera "Coelurus" and "Tanycolagreus", to be the sister group of Tyrannosauroidea.