(subclass Actinopterygii, superorder Osteoglossomorpha)
An order of freshwater fish that includes several families with fossil relatives. All have a single, soft-rayed, dorsal fin, low-placed pectoral fins, small, mid-ventral, pelvic fins, and a long-based anal fin. The order includes the Notopteridae (featherback), Hiodontidae (mooneye), Osteoglossidae (bony tongue), and Pantodontidae (butterfly fish).
Subjects: Zoology and Animal Sciences.