“Double-crested reptile”, was discovered in 1942 in Monument Valley in the Navajo country, Arizona, by native Jesse Williams. Based on these remains, which came from the Kayenta Formation, it was described in 1954 by Sam Welles as a new species of Megalosaurus, before new remains revealed it was a new animal. Welles gave it a new description, and name, in 1970.
Dilophosaurus lived during the Hettangian or Sinemurian stages of the Early Jurassic, about 200 to 190 million years ago. It was 6 meters (20ft) in length, over 1.8 meters (6ft) in height at the hips and 1000 pounds (454kg) in weight.
It belonged to the Dilophosauridae, a group of medium-sized early theropods that also included Cryolophosaurus, Dracovenator, and Zupaysaurus. Material for Dilophosaurus includes a number of specimens of varying degrees of completeness and ages, ranging from scattered fragments of an infant, to the incomplete subadult holotype specimen, to an incomplete adult specimen which was the first to preserve the distinctive crests, and more. The large crests for which it was famous may have been used for sexual display or intraspecific recognition, and would have been brightly colored. Several specimens have been discovered together and have been interpreted as evidence of group behavior, though this has been contested by other researches, leaving it open to debate. In addition, resting traces attributed to Dilophosaurus have been used to shed light on dinosaur posture, and track types from the Kayenta Formation have been attributed to Dilophosaurus.
Unlike its counterpart in the film but more like its counterpart in the novel Dilophosaurus is a full grow adult in the comics. It is highly unlikely the real-life Dilophosaurus was able to spit venom, or erect a colorful frill.
A Dilophosaurus attacked and killed Dennis Nedry as he attempted to deliver stolen embryos to his contact. A Dilophosaurus attacked a Jeep carrying Dr. Gustavus, Abby Nakajima and Derrick Hoyle. The Jeep crashed, and Abby and Derek escaped while the Dilophosaurus proceded to maul Gustavus, though he somehow escaped to show up alive later on, albeit badly injured by the attack.
Later on, a group of Dilophosaurus eggs were brought from Nublar to the mainland near San Carlos by Hurricane Bianca. Four years later, the animals were adults, and began to attack locals and animals, starting with a steer, followed closely by a couple named Juana de Vargas and Paco. The locals attributed the attacks to legendary night ghosts, or demons, called ‘hupia’, even when encountering the Dilophosaurus themselves.
Paco’s brother Águilar rallied a group of friends to combat the Dilophosaurus when they attacked the town, though there were several casualties, including Pedro, who was torn apart, and Cubano, who as blinded by venom and died in the ensuing explosive motorcycle crash, and José, who fell to his death. All of the Dilophosaurus were killed by gunfire or by falling into a canyon while pursuing the humans fighting them- except one, which, unbeknownst to anyone, still lurked in the nearby jungle with another clutch of eggs.
