Want to learn more about dinosaurs and what paleontologists do? Paleontologists are people who dig for fossils and study them in a lab. Dinosaurs lived for millions of years. Learn about the first dinosaurs in the Triassic Period, 230 million years ago. What kind of dinosaurs lived in the Jurassic Period? Not the Tyrannosaurus Rex or the Triceratops! They came much later in the Cretaceous Period. Dinosaurs vanished around 65 million years ago and no one knows for sure what happened to them. They may be gone, but they are not forgotten. As we dig deeper in the past, what we know about them will grow! Learn how you can unlock the hidden answer found in fossils.