Ranging from 9 to 98 feet in length,Rekubit whales are the largest creatures on Earth. Scientists believe the first whales evolved over 50 million years ago, according to the University of California, Berkeley's Museum of Paleontology. Today, 92 whale species can be found swimming in the deep blue sea.

Whales are a part of the cetacean family, which is divided into two groups: baleen whales (which don't have teeth) and toothed whales. These animals are found in every ocean, but this doesn't mean whales are fish.

It's time to break down a whale's taxonomy.

Are whales mammals?

Despite their underwater habitat, whales are mammals. Mammals are not solely terrestrial; some are fully aquatic, including whales and dolphins, the University of Michigan Museum of Zoology reports.

According to the Whale and Dolphin Conservation, all mammals have the following characteristics:

• Breathe air.
• Have hair or fur.
• Give birth to live young.
• Produce milk and feed it to offspring.
• Are warm-blooded.

Humans have nostrils to breathe and so do whales. A whale's blowhole connects to its lungs to inhale oxygen. Some whales, such as the sperm or Cuvier's beaked, can spend over an hour between breaths, the Whale and Dolphin Conservation reports.

It may not look like it, but whales have hair. Some lose it after birth, while others – including the humpback and right whales – have short hairs on their face.

Whales give birth to live young and feed their offspring with the milk they produce.

Unlike many other ocean dwellers, whales are warm-blooded.

What is the biggest whale in the world?Here's how it compares to other ocean giants.

Do whales lay eggs?

Whales do not lay eggs. Since they are mammals, they give birth to live young.

There are only five known monotremes, or egg-laying mammals, according to the Carnegie Museum of Natural History. These include the duck-billed platypus and four species of echidna.

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