The 500 Million Year History of Vertebrates

These are two primitive fish, even before vertebrates evolved jaws!

The first vertebrates on Earth evolved around 500 million years ago. They were fish in the ocean. Being vertebrates, they had backbones that helped them move more quickly, which means that they could escape from predators more easily.

Ocean fish are reminders of the most primitive vertebrates, but all vertebrates alive today share these first ocean fish as a common ancestor.

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What about a backbone do you think makes it possible for vertebrates to move more quickly than animals without a backbone?

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It's not just about the backbone itself. Think about what connects to the backbone.

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Vertebrates can move more quickly than animals without a backbone because their muscles can attach to the bones.

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