Description Deep under our feet, our planet is full of history. Fossils can teach us a lot about Earth. Look inside to find out what fossils are, how they are formed, and where you can find real-life fossils!. . Fossils is part of Decodables by Jump!, a comprehensive library of decodable leveled readers that follow a sequenced approach to phonics instruction. Young readers will enjoy colorful, photo-packed nonfiction as they follow a prescribed format supported by the science of reading that encourages reading development.