The Big Question: What's the difference between all the dinosaur periods?
That's what nine-year-old Lucy from Tring wants to know. It's certainly a big question!
Thankfully Lecturer Robin Beck from the University of Salford has managed to squeeze 150 million years of history into 2 minutes.
So what are the differences between the Triassic, Jurassic, and Cretaceous periods?
Check out other dinosaur-related Big Questions too: Can we bring dinosaurs back? and What was the first dinosaur?.