Dilophosaurus is a genus of theropod dinosaur from the Sinemurian stage of the Early Jurassic Period, about 193 million years ago. It measured around 7 metres long and may have weighed between 500 to 1,000 kilograms. The most distinctive characteristic of Dilophosaurus is the pair of rounded crests on its skull. These are considered to be too delicate for anything but display purposes.
Dilophosaurus is prominently featured in both the novel and film adaptation of Jurassic Park. It is depicted spitting blinding poison, and also has a retractable frill neck, much like a frill-necked lizard. There is no evidence to support either the frill or the venom spitting. In the film, Steven Spielberg, also reduced its size to 3 feet tall, in order to avoid confusion with the velociraptors.