As told by Mr. DNA:

A hundred million years ago, there were mosquitoes, just like today. And, just like today, they fed on the blood of animals. Even dinosaurs!

Sometimes, after biting a dinosaur, the mosquito would land on a branch of a tree, and get stuck in the sap.

After a long time, the tree sap would get hard and become fossilized, just like a dinosaur bone, preserving the mosquito inside.

Using sophisticated techniques, they extract the preserved blood from the mosquito, and...bingo! Dino DNA!

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