Name means: Two-Crested Lizard
Range: Early Jurassic (Sinemurian, 197-190 MYA) from Arizona, possibly Utah, Connecticut
Size estimate: 20-23 ft length, 800-900 lbs
Discovery: Samuel P. Welles, 1970
Classification: dinosauria, saurischia, therapoda, neotherapoda, dilophosauridae
Scientists have described only 5 skeletons of Dilophosaurus, all found in Arizona. Though Dilophosaurus ranked among the largest carnivores of its day, it still had a light build and delicate bones. The thin crests on the animals’ head likely served a display function of some sort. They were too thin for anything rougher than showing off. In life they may have been brightly colored to attract mates or to scare off rivals. The notch in its upper jawline resembles a feature found in fish-eating crocodiles. This leads some paleontologists to conclude fish made up a large part of its diet.
Footprints called Eubrontes may belong to Dilophosaurus. Eubrontes tracks have been found at the Johnson Discovery Site in St.George, Utah and Dinosaur State Park, Connecticut. If Dilophosaurus made Eubrontes tracks, they would form the most common fossil evidence for this type of dinosaur. They provide valuable clues on Dilophosaurus' lifestyle. The fact that these footprints occur near ancient brooks corroborates Dilophosaurus' fish-eating habits. Eubrontes traces found in St. George also show that Dilophosaurus could use its forelimbs to pull itself to its feet.
Jurassic Park catapulted Dilophosaurus to popular fame. But the real Dilophosaurus little resembles the Hollywood version. As this life-sized restoration shows, it grew much larger than its movie counterpart. The filmmakers added an extendable frill to the movie prop for storytelling reasons. The movie Dilophosaurus had to look harmless at first, but it needed to look scary when attacking. The frill made it look suddenly bigger while its bright colors enhanced the surprise. Real animals do use similar structures for defense. However, scaring prey with a frill during an attack risks scaring them off or forcing a counterattack. Finally, no evidence supports the idea that Dilophosaurus could spit poison. Spitting on fish with even poison doesn't make them easier to catch.