In 1848, miners in a quarry in Yorkshire, England, were astonished when they discovered the skeleton of a huge creature buried in the rock. It was Rhomaleosaurus, one of the most fearsome predators of the Jurassic seas. At the time, the seas were ruled by two kinds of marine reptile—the dolphinlike ichthyosaurs and lizardlike creatures with long necks known as plesiosaurs. Rhomaleosaurus belonged to the plesiosaur family.
■ When: 200–195 million years ago (Early Jurassic)
■ Fossil location: England, Germany
■ Habitat: Coastal waters
■ Length: 15–21 ft (5–7 m)
■ Diet: Fish, squid, and ocean reptiles
Rhomaleosaurus used its cone-shaped fangs to attack large prey. Like a crocodile, it may have twisted its victims around violently to tear their bodies apart and make them easier to swallow.
Like large sea animals today, Rhomaleosaurus may have had a pale belly and a dark back. This pattern, known as countershading, is a type of camouflage—it makes marine animals harder to see both from above and below.
Rhomaleosaurus swam by beating its four powerful flippers, using them like wings to “fly” through the water in the same way as penguins move underwater today.