The teeth were long, curved, thin, and compressed sideways. The mandible was slender and delicate at the front, but deep at the back.
It had a pair of longitudinal, plate-shaped crests on its skull, similar to a cassowary with two crests. The snout was narrow, and the upper jaw had a gap or kink below the nostril. It was slender and lightly built, and the skull was proportionally large, but delicate. At about 7 meters (23 ft) in length, with a weight of about 400 kilograms (880 lb), Dilophosaurus was one of the earliest large predatory dinosaurs, though it was smaller than some later theropods.
