Which dolphin species is the only living member of the genus Grampus?

The only living member of the genus Grampus is Risso's dolphin.

Its scientific name is Grampus griseus, and it is the sole living species assigned to Grampus. The dolphin belongs to the family Delphinidae, although its heavy body, rounded head and dramatic pale scarring make it look quite different from the sleek, familiar image of a bottlenose or common dolphin.

Risso's dolphins occur in oceans around the world, especially in cold-to-temperate waters and near continental shelves. They are powerful divers that use echolocation to locate squid and other prey. Adults may become heavily scarred through social interactions, parasite damage and encounters with prey, gradually developing a mottled gray-to-white appearance.

The genus name can cause confusion because “grampus” was once commonly used for the orca. Historical taxonomic proposals even suggested replacing Grampus, but later catalogs treated those alternatives as synonyms. Spinner dolphins, dusky dolphins and common dolphins belong to different genera and are not members of Grampus.