Amiids

Amiids are a family of basal ray-finned fish that was once very common in the freshwater courses of the Mesozoic and early Cenozoic, specially in North America. Today it is only represented by one single non-endangered species. They live in slow-moving backwaters and ox-bow lakes which can have low levels of oxygen, to which these fish react by gulping air into its swim bladder, to work as a primitive lung, which is also done by many other fish. Amiids are large predators, equipped with long bodies and short snouts to engulf larger prey and swallow them whole.