Dinosaurs roamed Earth between 230 million and 65 million years ago. That's not only long before the present day, but also long before Homo sapiens were around at all. Without fossils, we might not know anything about these fierce and interesting prehistoric animals. Young explorers will learn how fossils form, the different kinds of dinosaur fossils that scientists study, and just what we've learned from these cool fossil finds. Detailed photographs aid readers' understanding while fact boxes add more context to key science concepts.