Dilophosaurus

Family

Ornithischia

Era

Early Jurassic, 190 to 200 million years ago

Where he lived?

Western US and possibly China

Weight

400Kg

Height

1,7m

Length

The Dilophosaurus Wetherilli was a theropod dinosaur that lived during the Early Jurassic period, approximately between 195 and 183 million years ago, in what is now North America. Its name, meaning “two-crested lizard,” refers to the two prominent arched crests that adorned its skull.

Discovery and Research

The first Dilophosaurus fossils were discovered in 1940 in northern Arizona, United States. Initially, these fossils were assigned to the Megalosaurus genus and described as Megalosaurus Wetherilli in 1954 by paleontologist Samuel P. Welles. However, in 1970, after the discovery of additional specimens revealing the presence of distinctive cranial crests, Welles established a new genus, naming it Dilophosaurus.

Physical Characteristics

The Dilophosaurus was a medium-sized theropod, estimated to be about 7 meters long and weighing approximately 400 kilograms. It had a slender and lightweight build, with a proportionally large but delicate skull. The snout was narrow, and the upper jaw had a curvature or gap beneath the nasal cavity. The two arched crests on its skull, formed by nasal and lacrimal bones, are among its most distinctive features. While the exact function of these crests is unknown, it has been suggested that they might have been used for visual displays, species recognition, or sexual selection.

The Dilophosaurus’s jaw was thin and delicate at the front but deeper towards the back. Its teeth were long, curved, and laterally compressed, with serrated edges on both sides. The teeth of the lower jaw were significantly smaller than those of the upper jaw. Its neck was long, and the cervical vertebrae were hollow and lightweight, granting it flexibility and agility. The forelimbs were powerful, with a long and slender humerus. Its hands had four fingers: the first was short but robust and bore a large claw; the next two were longer and thinner with smaller claws; and the fourth finger was vestigial. The hind limbs were strong, with robust femurs and feet equipped with large claws.

Diet and Feeding

As a carnivore, the Dilophosaurus primarily fed on other animals. Its size and agility allowed it to hunt fairly large prey, and it is likely that it also fed on fish and small reptiles. The structure of its jaws and teeth suggests that it was adapted for grasping and tearing flesh, though the delicacy of its skull indicates that it might have avoided direct confrontations with very large or dangerous prey.

Habitat and Distribution

Fossils of Dilophosaurus have been found in the Kayenta Formation in northern Arizona, indicating that it inhabited what is now the southwestern United States. During the Early Jurassic, this region had a warm, semi-arid climate, with environments ranging from riverine areas to alluvial plains. This setting would have provided a variety of suitable habitats for a predator like Dilophosaurus.

Popular Culture and Misrepresentations

The Dilophosaurus gained notoriety in popular culture following its appearance in the 1993 film Jurassic Park. However, its portrayal in the movie significantly differs from paleontological evidence. In the film, it is depicted as a small dinosaur with the ability to extend a frill and spit venom, characteristics that have no scientific support. In reality, the Dilophosaurus was considerably larger, and there is no evidence that it possessed a frill or the ability to spit venom.

Conclusion

The Dilophosaurus Wetherilli is a remarkable theropod dinosaur known for its distinctive cranial crests and its role as one of the first large predators of the Early Jurassic. While some aspects of its biology and behavior remain uncertain, the available fossils provide valuable insight into the diversity and evolution of early theropods.