SuperCroc likely measured about 40 feet (12 meters) long and weighed as much as ten tons. Its jaws alone measured 6 feet (1.8 meters)—as long as a tall human.

Paul Sereno’s team came across the Sarcosuchus imperator jaws in the first hour of their Niger fossil hunt. They quickly realized they did not belong to a dinosaur. “We had never seen anything like it,” he says.