STEPHANIE WARREN DRIMMER is a longtime writer for National Geographic Kids magazine and has written several books for Nat Geo Kids, including Hey, Baby!, The Book of Heroines, Surprising Stories Behind Everyday Stuff, and Mastermind. DR. STEVE BRUSATTE (expert contributor) is a paleontologist and leading authority on dinosaurs and dinosaur evolution. He is a professor at the University of Edinburgh and author of the New York Timesbest-selling book Rise and Fall of the Dinosaurs.