A giant meteor blasts an enormous crater into Earth's surface, causing the end of what scientists call the Age of Dinosaurs. Gail Gibbons presents the most recent and up-to-date theories about the history of dinosaurs and dinosaur discoveries. She discusses the Triassic, Jurassic, and Cretaceous periods and the non-bird dinosaurs that lived during each time.

Each dinosaur is explored in just the right amount of detail for young paleontologists, as this book brings these magnificent creatures to life again. Gail Gibbons's books have won many honors, including the Washington Post/Children's Book Guild Nonfiction Award and the NSTA Outstanding Science Trade Book awards.