Prepomatodelphisbelongs to the platanistid subfamily Pomatodelphininae, which is distinguished from the South Asian [river dolphin] in having a flattened rostrum, a transversely expanded posterior end of the premaxilla, an eye and bony orbit of normal size, and nasal bones not reduced in size but wide transversely. Features distinguishing Prepomatodelphis from Pomatodelphis include smaller size, cranium with surface of the premaxillary sacfossa undulating, having in its midpart a sulcus bounded both medially and laterally by a ridge, and sloping ventrally at both its medial and lateralmargins, and zygomatic process of squamosal very deep dorsoventrally in the posterior part.