An unmarked group of the fish subclass Neopterygii consisting of several fossil orders (see Phylogeny below) and the extant orders, Lepisosteiformes and Amiiformes. The holosteans are descended from the older Chondrostei and in turn are ancestral to the great mass of modern bony fishes, the Teleostei. It is not certain whether holosteans evolved from a single stock or multiple stocks of the Chondrostei.