ZAP’S FACTS!
WHALES

Whales evolved from four-legged mammals that walked on land.

Their closest living cousin is the hippo - and they have leg bones inside their bodies to prove it.

2 min read
Whales evolved from four-legged mammals that walked on land.
THE FULL STORY

It’s hard to believe, but the biggest animals in the ocean started out as small, furry, four-legged mammals on land. About 50 million years ago, a wolf-sized creature called Pakicetus lived on the edges of warm rivers and oceans in what’s now Pakistan. It looked nothing like a whale - but it’s a direct ancestor of every whale alive today.

Over the next 8 million years, descendants of Pakicetus gradually moved from land to water. Their legs shrank. Their tails grew flatter. Their nostrils migrated to the top of their head, becoming a blowhole. Their bodies streamlined into the shape we know today.

Modern whales still carry evidence of that old life on land. They have small leftover hip bones floating inside their bodies, no longer connected to any limbs but still there from 50 million years ago. And their closest living relative isn’t another sea creature - it’s the hippopotamus, which shares a common ancestor with whales.

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