The relationships of "Dromaeosaurus" are unclear. Although its rugged build gives it a primitive appearance, it was actually a very specialized animal. It is usually given its own subfamily, the Dromaeosaurinae; this group is thought to include "Utahraptor", "Achillobator", "Adasaurus", and possibly "Deinonychus". However, the relationships of dromaeosaurs are still in a state of flux.