Which dolphin species has a bulbous head and no distinct beak?

Risso's dolphin is the dolphin species with a bulbous head and no distinct beak. Its rounded forehead and short, blunt snout give it a noticeably different profile from the long-beaked dolphins often seen leaping near boats. The species is scientifically named Grampus griseus.

Risso's dolphins are born with darker coloration, but adults often become pale or almost white as scars accumulate across their bodies. These scars are especially prominent because older skin does not fully repigment. The marks can result from social interactions, including competition between males, as well as encounters with prey such as squid.

The species is a member of the oceanic dolphin family, even though its appearance can seem unusual compared with bottlenose or spinner dolphins. Bottlenose dolphins have a clearly defined beak, while spinner dolphins have a slender beak and a more streamlined head. Risso's dolphins commonly live offshore and feed heavily on squid and other deep-water prey.