Turtle Tears

Sea turtles are magnificent swimmers, migrating thousands of miles each year. But when the first turtles moved from the land to the sea more than a hundred million years ago, they didn't have this ability, says Ren Hirayama, a paleontologist at Teikyo Heisei University in Chiba, Japan. Hirayama found a nearly complete fossil of the oldest known sea turtle in a 110-million-year-old rock collected from the site of an ancient Brazilian sea. The little turtle, barely eight inches long, was probably a young adult. Hirayama noticed that the bones in its limbs were not fused into rigid paddles as they are in living sea turtles. The fossil turtle had movable digits, like a freshwater turtle's. "It would not have been a very strong swimmer," says Hirayama. The turtle's skull, however, showed that it was indeed a marine animal: Hirayama found traces of enormous tear glands. When swimming in salty seas, ...