largest mammal order
North Atlantic Right whales (Eubalaena glacialis) are big, but they're not the biggest whales. That distinction goes to the Blue whale (Balaenoptera musculus), the largest animal on Earth. While the Orca, or Killer whale size of up to 31 feet make it the largest dolphin. The Sperm whale on the other hand may not be the biggest whale, but it has the biggest brain to have ever existed on Earth. Below is a comparison chart of whale sizes. To learn more whale facts follow the links below.