An order of actinopterygian fishes in the subclass Neopterygii. Amiiformes plus several related fossil orders comprise the Halecomorphi, a well-developed group known from the middle Mesozoic. The Amiiformes comprise several families that persisted into the Cenozoic era; but only one, the Amiidae, survived to the present and it consists of a single species, Amia calva, the bowfin. The fossil amiids are from freshwater deposits, the oldest of which are of Jurassic age. The other halecomorphs were marine species.