Allodelphinidae

Allodelphinidae is a family of primitive platanistoid river dolphins found in marine deposits in the eastern North Pacific region, Alaska, and Japan.

Arktocara is an extinct genus of river dolphin from the Oligocene epoch of Alaska, containing one species, A. yakataga. Having been discovered in 25-million-year-old strata near the 60th parallel north, it is perhaps the oldest-known crown toothed whale and the northmost river dolphin discovered. It was a member of the now-extinct family Allodelphinidae, along with the genera Allodelphis, Goedertius, Ninjadelphis, and Zarhinocetus. It measured approximately , comparable to its closest living relative, the South Asian river dolphin, which measures . However, the animal probably had an elongated

Allodelphis is an extinct genus of whale belonging to Allodelphinidae found in marine deposits of the eastern North Pacific.