From ancient megalodons to fearsome Great Whites, this book tells the complete, untold story of how sharks emerged as Earth's ultimate survivors, by world-leading paleontologist John Long. Sharks have been fighting for their lives for 500 million years and today are under dire threat. They are the longest-surviving vertebrate on Earth, outlasting multiple mass extinction events that decimated life on the planet. But how did they thrive for so long? By developing superpower-like abilities that allowed them to ascend to the top of the oceanic food chain. John Long, who for decades has been on the cutting edge of shark research, weaves a thrilling story of sharks' unparalleled reign. The Secret History of Sharks showcases the global search to discover sharks' largely unknown evolution, led by Long and dozens of other extraordinary scientists. As the tale unfolds, Long introduces an enormous range of astonishing organisms: a thirty-foot-long shark with a deadly saw blade of jagged teeth protruding from its lower jaws and bizarre sharks fossilized while in their mating ritual. With insights into the threats to sharks today, how they contribute to medical advances, and the lessons they can teach us about our own survival, The Secret History of Sharks is a riveting look at scientific discovery with ramifications far beyond the ocean.