Squalodelphinidae

Squalodelphinidae is a family of primitive platanistoid river dolphins found in marine deposits in the eastern Pacific, western Atlantic, and Europe.

Description
Distinguishing features of Squalodelphinidae include a moderately elongated and tapered rostrum, posterior cheek teeth being single-rooted but retaining accessory denticles, and marked skull asymmetry. Members of the family can be differentiated from the South Asian river dolphin by their shorter rostrum.