Book excerpt: Fossils are one of the most important tools we have for learning about long-extinct wildlife. A True Book: Earth Science series presents fascinating facts and fun activities that will engage the budding earth scientist, while exploring the fields of geology, meteorology, ecology, and more. This series includes an age appropriate (grades 3-5) introduction to curriculum-relevant subjects and a robust resource section that encourages independent study. In the 4.6 billion years since Earth was formed, many plant and animal species have come and gone. Readers will discover how fossils are formed, how paleontologists search for them, and what kinds of information they can provide.