Not all giant predators were marine reptiles. A 15-foot-long (five-meter-long) Xiphactinus—a fish with a trap-door mouth—pursues a much smaller Apsopelix fish. Long-necked Thalassomedon heads closer to the surface. And Archelon—at 15 feet (five meters) the largest sea turtle ever—obscures light overhead.QTVR by NGM Art, pandromeda.com