Trotting on its hind legs through what’s now Arizona, a dino named Dilophosaurus searches for prey. Spotting an SUV-size herbivore in the distance, the 20-foot-long predator picks up its pace. Attacking the animal, it uses sharp claws and strong arms to hold its prey while it takes a bite.
Dilophosaurus means “double-crested lizard” in Greek, a name that refers to its headgear. The dinosaur had two thin, bony crests running from its snout to behind its eye socket. Because the bones were likely covered in keratin (the same substance as rhino horns), scientists aren’t sure about the crests’ shape. But paleontologists think the keratin-covered headgear was probably brightly colored and used to impress mates. The crests might’ve even been topped with eye-catching inflatable air sacs like some modern birds have on their throats to show off to other fliers.
Paleontologists have discovered that the crests and other bones were reinforced with air pockets in a honeycomb structure. This would have made the skeleton strong but light, which allowed the animal to grow larger than other dinos before it. In fact, Dilophosaurus was North America’s first large meat-eating dino, weighing around 1,500 pounds.
When it roamed what’s now North America during the Jurassic period, about 195 million years ago, Dilophosaurus was one of the fiercest predators around. But about 50 million years later, Allosaurus would replace Dilophosaurus as the top predator; Tyrannosaurus rex took the top spot another 77 million years after that.