Dilophosaurus is an extinct genus of theropod dinosaur that lived during the Sinemurian age (early Jurassic period), around 193 million years ago. It is known by a single known species Dilophosaurus wetherilli. It was one of the largest carnivores of its time.

Physical description

Research on the few specimens suggested that they did not have any sexual dimorphism. Both male and female were similar when it comes to their skeleton structure. Dilophosaurus was a slender, fast-moving bipedal predator along with two thin, bony rounded crests on their head. They had short with three-fingered hands and strong legs with 4-toes feet. They also had a curved, S-shaped neck.

Range and Discovery

Three Dilophosaurus fossils have been unearthed from the United States; all found together in the state of Arizona. Another fossil has been unearthed from China (Asia). Fossilized bone samples similar to that of a Dilophosaurus skeleton have been found in several places around the world.

The first Dilophosaurus fossil specimens were unearthed by Sam Welles in 1942 in the Kayenta Formation in Arizona. The spot was found by Jesse Williams, in 1940. Two specimens – holotype UCMP 37302 and the paratype UCMP 37303 were taken to Berkeley for cleaning and mounting by Wann Langston’s team. In 1954, Welles gave the name Megalosaurus wetherilli in honor of John Wetherill.

Behavior and Habitat

Fossil samples suggest that they roamed in groups. It is believed that they were relatively fast runners. Some of the fossilized footprints had imprints of claw-tips. Their legs were around 1.65 meter in length, and its stride was around 2.13 meter long. They lived near streams, rivers as well as other water sources.

Fun Facts

• The name Dilophosaurus was given by Samuel P. Welles in 1970.
• The crests of Dilophosaurus were for attracting mates or intimidating a rival. Recent studies suggest that it was actually for intra-species recognition.
• Fossilized footprints assigned to this genus have been discovered in Höganäs Formation in Vallåkra and Sala, Sweden. The footprints suggest that they lived in herds.
• The existence of a proposed species, D. breedorum, was concluded to an adult Dilophosaurus wetherilli.
• All the fossil samples found in the United States are now at the University of California’s Museum of Paleontology at Berkeley, United States.
• They did not have a great bite force compared to other dinosaurs.
• Dilophosaurus is featured in Michael Crichton’s Jurassic Park as well as its movie adaptation. Unlike as it is shown on the Jurassic Park film, there is no evidence of its poison spitting. They also did not have any frill (also known as flaps) as suggested by the film.