Osteoglossids are basal (primitive) fish from the lower Tertiary and are placed in the actinopterygiid order Osteoglossiformes. As traditionally defined, the family includes several extant species from South America, one from Africa, several from Asia, and two from Australia. Today Arapaimidae is often regarded as a separate family, which includes the arapaimas and the African arowana. Consequently, the South American genus Osteoglossum, and the Asian and Australian genus Scleropages are the only extant genera that remain in the osteoglossid family. Arapaimidae and Osteoglossidae split about 220 million years ago (Mya), during the Late Triassic.
Within Osteoglossidae, the South America Osteoglossum arowanas diverged from the Asian and Australian Scleropages arowanas about 170 Mya, during the Middle Jurassic.