Before dinosaurs, before trees — even before Saturn had its rings – there were sharks. The fierce predators have been swimming in our oceans for hundreds of millions of years, standing the test of time as they survived all five of Earth's mass extinction events. Now, though, many of them face unprecedented threats, from overfishing to climate change. But there's a movement underway to protect sharks — and to change their public image, which suffered after the classic movie Jaws. On this episode, we explore the secret lives of sharks, and what can be done to help these ancient predators survive. We learn about the history of sharks, and what's made them so adaptable; hear about how some fishermen are helping to save them; and find out what the historical record can teach us about the largest, most fearsome shark to ever exist — the megalodon. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy