Xiphactinus (from Latin and Greek for "sword-ray") was a large, 4.5 to 5 m (15 to 20 feet) long predatory bony fish that lived in the Western Interior Sea, over what is now the middle of North America, during the Late Cretaceous. When alive, the fish would have resembled a gargantuan, fanged tarpon (to which it was, however, not related). The Portheus molossus described by Cope is a junior synonym of the species. Skeletal remains of Xiphactinus have come from Kansas, Alabama, and Georgia in the United States, as well as Europe and Australia it would have eaten Hesperornis and was eaten by the top predator of Cretaceous seas Hainosaurus.