Underwater World (145-65 Million Years Ago)
Become immersed in the underwater world of the Cretaceous Period, 80 million years ago, when North Dakota was covered by inland seas. Walk on the seafloor “underwater” with sound effects and lighting simulating sun on the water’s surface. View a wall-size mural depicting North Dakota as it appeared 80 million years ago.
Featured are suspended skeleton replicas and skeleton parts of some of the creatures that would have inhabited the seas:
- Plioplatecarpus, a 24-foot-long mosasaur (a large marine lizard-like predator) found near Cooperstown
- Xiphactinus, a 16-foot-long tarpon-like fish
- Archelon, a 12-foot-long giant sea turtle
- Hesperornis, a 5-foot-tall diving seabird
Fossils of some smaller fish and other animals are displayed with a magnifier for up-close viewing.