Sharks. Lords of the Seas from Prehistory to the Present. Is it true that carnivorous dinosaurs were the greatest predators ever to walk the Earth? Wrong: ferocious sharks ruled the seas 150 million years before them - and they're still with us today. The lives and secrets of 20 sharks, and some of their closest relatives, from the Devonian to the present day, told in light of the latest discoveries and illustrated with thrilling realism.