What Is a Large Sea Animal Related to the Dolphin?

Large Cetacean Relatives of Dolphins

Several large sea animals are related to dolphins. The orca, or killer whale, is the largest member of the dolphin family. Other relatives include pilot whales and false killer whales. Bottlenose dolphins are also relatively large for dolphins.

More broadly, all whales—including humpbacks and blue whales—are cetaceans and share a common ancestry with dolphins.