Is a killer whale actually a dolphin?

Yes.The killer whale, or orca, is the largest member of the dolphin family, according to NOAA Fisheries. 'Killer whale' is just its old common name.

What's actually true

Killer whales are the biggest dolphins. Orcas are called killer whales, but NOAA Fisheries lists them as the largest member of the dolphin family. The old name stuck, which is why the biggest dolphin on the planet still goes by 'whale'.

Takeaway: Orcas belong to the dolphin family, and they're its largest member.

Why people believe it

Orcas are huge, black and white, and nothing like the small grey dolphins people picture, so 'whale' feels right. The name 'killer whale' is the one on most signs, in films and in nature shows. And because people think of whales and dolphins as two separate kinds of animal, the idea that a famous 'whale' belongs to the dolphin family sounds like a contradiction.

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