Which anatomical feature is a key identifier of a harbour porpoise head, setting it apart from many dolphin species?

Answer

A short, blunt, poorly demarcated beak

Harbour porpoises have small, rounded heads characterized by a short beak that is often so poorly demarcated it is barely noticeable, lacking the pronounced rostrum common to many dolphins.

Which anatomical feature is a key identifier of a harbour porpoise head, setting it apart from many dolphin species?
animalmammalcetaceanporpoise