In the 1990s, after watching Jurassic Park and hearing about Dolly the sheep, many children hoped that scientists would develop the capacity for cloning dinosaurs that could roam again on the Earth. (Although, after watching Jurassic Park, they should have known better). Few researchers had said that dinosaur DNA samples had survived until the present day, but no one was quite sure how long it takes for DNA to unravel. Now, researchers have figured out that DNA’s lifespan is longer than we thought - but still not long enough to make dinosaur cloning possible.