E. D. Cope and O. C. Marsh were 19th-century paleontologists whose friendship couldn't withstand their professional rivalry. Their competitive natures led to the frenzied unearthing of hundreds of dinosaur fossils across North America, many of which can still be seen in museums around the world. The captivating tale of these scientists unfolds in this absorbing book, which also includes a timeline, sidebars, and fact boxes offering much information about paleontology, dinosaurs, and excavations as well as photographs and images to further elucidate essential science concepts.