What lurked in Earth’s oceans millions of years ago? This volume introduces readers to amazing marine fossils that have been found in oceans, creeks, lakes, and other areas that were once underwater. Readers will examine the fossils of ancient trilobites and other marine animals, as well as marine plants. They’ll learn to think like a paleontologist as they discover the remains of prehistoric fish and marine dinosaurs. Color photographs, diagrams, and sidebars allow readers to connect with the text and expand their understanding of the ancient underwater world.