Dilophosaurus

Dilophosaurus was a prominent apex predator of the Early Jurassic, known from abundant, well-preserved remains found in the Kayenta Formation of Arizona. Reaching roughly seven metres in length, it was considerably larger than portrayed in popular culture, weighing close to four hundred kilograms. Its most famous feature was a set of thin, delicate bony crests arching along the top of its skull, which were far too fragile for combat and likely served as social or visual displays. Contrary to cinema fiction, there is no evidence it could spit venom or possessed a neck frill. Recent anatomical studies demonstrate Dilophosaurus had a powerful jaw and robust forelimbs, making it a capable hunter of contemporaneous prosauropods and early armoured dinosaurs.

A pair of delicate, semicircular bony crests ran along the top of its skull, probably used for display.

Where and when

Dilophosaurus lived in the Early Jurassic, from 193 to 183 million years ago (Sinemurian-Pliensbachian age). Its remains come from United States, in the Kayenta Formation.

The numbers

Length 6.5 m (estimates run from 6 to 7 m). Mass about 400 kg. Hip height about 1.8 m. That is 3.8 human-lengths, or 0.58 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Dilophosaurus with a bus Place on the timeline