Coelacanth This fish was thought to be extinct for millions of years, but was rediscovered in 1938. It is a living fossil and one of the most unusual fish in the world.
MegalodonThis giant shark is estimated to have been up to 60 feet long and weighed up to 50 tons. It is one of the largest predators that has ever lived.
HelicoprionThis shark had a spiraled jaw that was used to crush its prey. It is one of the most bizarre-looking sharks that has ever lived.
LiopleurodonThis plesiosaur was up to 50 feet long and had a long neck and flippers. It is one of the largest marine reptiles that has ever lived.
Plesiosaurs
These marine reptiles were closely related to dinosaurs and lived in the Jurassic and Cretaceous periods. They came in a variety of shapes and sizes, from the small Compsognathus to the giant Elasmosaurus.
Ichthyosaurs
These marine reptiles were also closely related to dinosaurs and lived in the Triassic, Jurassic, and Cretaceous periods. They were streamlined swimmers and some species could grow up to 60 feet long.
Archelon
This giant sea turtle was up to 13 feet long and weighed up to 2,000 pounds. It is the largest sea turtle that has ever lived.
Xiphactinus
This giant fish was up to 50 feet long and had a long, sharp beak. It was one of the top predators in its environment.
Stethacanthus
This strange-looking fish had a large, paddle-shaped dorsal fin that was covered in sharp spines. It is one of the most unusual fish that has ever lived.
Dunkleosteus
This giant armored fish lived in the Devonian period and was one of the most fearsome predators of its time.