Vanished Ocean: How Tethys Reshaped the World (Repost)

Six million years ago, a vast ocean–which scientists have named Tethys–vanished from the face of the earth. How could such a huge body of water simply disappear? More interesting, how is it possible for scientists to know with certainty that Tethys existed for a quarter of a billion years, a period that includes the entire "Age of Dinosaurs" and almost all of the "Age of Mammals," right up to the point when our distant ancestors began to walk upright.