Dilophosaurus

Dilophosaurus is a theropod dinosaur from the Early Jurassic of the United States of America. It was officially named in 1954 by Samuel Paul Welles. It was one of the earliest theropods to reach a relatively large size, and was thought to be a species of Megalosaurus before finally being described as its own genus.

## Physiology

Dilophosaurus was a mid-sized theropod with a semi-bulky body, a long tail, long arms with three fingers on each hand, a moderately long neck, a mid-sized, conical head with large jaws, and two large crests atop its head. Most of its body would have been covered in short, fuzz-like feathers.

## Diet

Dilophosaurus was a predator, preying on small crocodylomorphs, small cynodonts, pterosaurs, fish, small ornithischians, and smaller theropods. Its large teeth were used for getting a hold of struggling prey, and a notch in its upper jaw would have helped in capturing them as well.

## Ecology

Dilophosaurus's crests were originally thought to be for attracting mates and warding off rivals; however, a team of scientists have argued that these crests were only used for recognition by other members of its species. Due to a large quarry containing many individuals, people may regularly assume that Dilophosaurus lived in packs; even if there are alternate explanations (like a flash flood picking up dead individuals and depositing them in a certain area), it would make sense for a large theropod with large crests to live in large groups, as every member of the gang would be able to observe and interpret each other's sexual status. A parallel trackway indicates that it was able to swim (although it can be inferred that all animals could swim to some extent); adding onto the fact that it had long teeth and a notched upper jaw, we can assume that it included fish in its diet. However, its robust skull and relatively average bite force allowed it to tackle large animals; in addition to this, even though its lower leg was slightly shorter than its upper leg, it had generally long legs, and so, it would have been a fast runner, capable of catching up to (and possibly even outrunning) its prey.

## In popular culture

Dilophosaurus was first introduced to the public in the 1990 novel *Jurassic Park*, where it was depicted as able to spit venom, aiming for the eyes of its target (in order to blind it) before killing it off with a venomous bite; on the other hand, this was acknowledged to be creative license by the author (besides, all the other carnivorous theropods in the book could envenom their prey, so it was only slightly more notable than they were). This was made more egregious in the 1995 movie adaptation of the novel, where the theropod was given a retractable neck frill that would open whenever it attacked; as well as this, it was downsized to a length of 3.4 meters just so the audience wouldn't confuse it with "*Velociraptor* *antirrhopus*" (even though it would be assumed that the dilophosaur's skull shape and large head crests would be enough to distinguish it from the dromaeosaur). Since then, this depiction has been perpetuated in every major piece of media containing Dilophosaurus; the only piece of media to deviate from this trend was the 2001 documentary *When Dinosaurs Roamed America*.