Contrary to what the film Jurassic Park may have led you to believe, Tyrannosaurus rex wasn't the largest—or scariest—dinosaur to ever roam the land. That honor goes to Spinosaurus, a genus of predators whose members could grow up to 50 feet long. They roamed North Africa during the mid-Cretaceous Period, around 100 million years ago.

Learn more about Spinosaurus—and the era's other fearsome creatures, which included carnivorous crocodiles and enormous flying reptiles—by watching the TED-Ed video below.

[h/t The Kid Should See This]