 Other than "Hupehsuchus", little else is known about "Nanchangosaurus" relatives.They have sometimes been referred to as ancestors of the ichthyosaurs, because of their streamlined shape, long jaws, and paddle-like hands, as well as the discovery of polydactyly in the fins of "Hupehsuchus", just like the ichthyosaurs.However, a gap in the skulls suggests that they may be related to archosaurs, instead.