Spinosaurus has made history as the first known swimming dinosaur. In our story—with exclusive photos—we detail how a newfound fossil tail is changing what we know about how and where dinosaurs lived. For more historic stories like this, subscribe to National Geographic: https://on.natgeo.com/2YhJYHJ | National Geographic History

In this clip, the Dinosaur Train Submarine finds a clutch of archelon babies and possibly their mother! Play Dinosaur Train games and watch full episodes on http://pbskids.org/dinosaurtrain | PBS KIDS