Main Insights
- The true Dilophosaurus was much bigger than its "Jurassic Park" representation, reaching lengths of over 20 feet (6 meters).
- Contrary to the film's portrayal, no scientific findings support the idea that Dilophosaurus possessed a neck frill or the ability to eject venom.
- The unique crests on its head may have served purposes such as attracting mates or regulating body temperature, and its jaw strength was greater than earlier estimates suggested.
If you've been following our series on dinosaurs, you're likely tired of hearing complaints about the 1993 film "Jurassic Park." Don't get us wrong — we love the movie, but it did make some errors. For instance, the Velociraptor depicted were far larger than reality, and there's no evidence to suggest T. rex had vision limited to moving objects.
No creature has been more inaccurately portrayed by this franchise than the crested hunter Dilophosaurus. Interestingly, it was one of the few dinosaurs in "Jurassic Park" that actually existed during the real Jurassic period.
Times Change
Every non-avian dinosaur was part of a geological era known as the Mesozoic, which is split into three periods: the Triassic, Jurassic, and Cretaceous.
The Cretaceous period concluded dramatically with a mass extinction 66 million years ago. Birds were the sole dinosaur lineage to survive this global disaster.
Their relatives enjoyed a long reign. The earliest dinosaurs emerged approximately 243 to 231 million years ago in the Triassic period. This era, rich in reptilian variety, transitioned into the Jurassic around 199 million years ago.
Before this shift, most meat-eating dinosaurs were relatively small. Dilophosaurus signaled the arrival of larger predators. This creature inhabited what is now Southwestern North America during the early Jurassic, roughly 183 to 193 million years ago.
Dilophosaurus stretched over 20 feet (6 meters) in length, earning it the title of the largest known land animal in North America at the time. It dwarfed many of the carnivorous dinosaurs that came before it.
This makes it odd that the "Jurassic Park" Dilophosaurus is depicted as small enough to sit beside actor Wayne Knight in his jeep.
Nedry's Nightmare
Knight portrayed Dennis Nedry, a frustrated computer programmer in the first "Jurassic Park" film. After betraying his employer and putting lives at risk, Nedry meets his fate when a wandering Dilophosaurus devours him inside a park vehicle.
The antagonist suffers a similar demise in Michael Crichton's "Jurassic Park" novel, which inspired the movie. In the book, the characters are informed: "Researchers once believed [Dilophosaurus'] jaw muscles were too feeble to hunt, assuming they were mainly scavengers. However, it's now understood they were venomous."
Stephen Spielberg's team added a dramatic neck frill to their movie Dilophosaurus, resembling those used by present-day frilled lizards to intimidate foes. After revealing this feature, the small dinosaur mimics a spitting cobra, ejecting venom into Nedry's eyes.
A Carnivore's Toolkit
No scientific findings support the idea that the actual Dilophosaurus possessed venom or a flexible neck frill. The deadly predator that kills Dennis Nedry has been labeled as "the most fictionalized dinosaur in Jurassic Park."
However, let's revisit the novel's quote. Crichton didn't invent the scavenger theory. Samuel P. Welles, the paleontologist who named Dilophosaurus in 1970, speculated that the creature might have been a scavenger.
Beneath the dinosaur's nasal openings, there's a unique notch on each side of its upper jaw. Known as the "subnarial gap," this feature is located where two separate jaw bones meet, both equipped with teeth.
Welles believed these notches indicated that the bones were poorly connected, suggesting that Dilophosaurus lacked a powerful bite. By the time Crichton's book was published, there had been extensive discussion about this dinosaur's dietary preferences.
Citing the supposedly "weak" jaw structure, some researchers proposed that Dilophosaurus primarily fed on carrion. Another theory speculated that Dilophosaurus was adept at fishing, using its elongated teeth and jaws to catch slippery fish.
Modern Reassessment
Recent studies have reshaped our understanding of this creature.
On July 7, 2020, the Journal of Paleontology released a study re-examining five Dilophosaurus specimens. Researchers Adam D. Marsh and Timothy B. Rowe discovered that the maxilla-premaxilla connection was more robust than Welles had believed. They also identified scaffold-like structures on the lower jawbones, indicating strong muscle attachments.
These findings suggest that Dilophosaurus possessed formidable jaws. (Bite marks on the bones of a Sarahsaurus — a sizable herbivore from the same era — might have been made by a hungry Dilophosaurus.)
Strange Headgear
Marsh and Rowe highlighted the dinosaur's most distinctive trait: its striking head crests.
The name Dilophosaurus translates to "two-crested lizard," referring to the pair of bony ridges along its skull. The exact shape of the crests remains uncertain, as no complete specimens have been found.
Marsh and Rowe noted in their study that the crests were "almost certainly enveloped in keratin or keratinized skin." Keratin, for context, is a fibrous protein present in hair, nails, claws, horns, and similar animal structures.
Certain contemporary birds, such as the formidable cassowary, possess bony head crests coated with keratin-based material. These layers can make the crests appear much larger than the bone beneath.
It's possible that Dilophosaurus appeared even more extravagant than its skeletal remains imply.
Tracing the Past
The purpose of the dinosaur's dual crests remains a mystery. While some speculate they were used to attract mates, others suggest they may have played a role in controlling body temperature.
Dilophosaurus' evolutionary relationships are also a hot topic. Marsh and Rowe highlighted anatomical similarities linking it to two other crested predators: Argentina's Zupaysaurus and Antarctica's Cryolophosaurus.
Fossilized footprints of large carnivorous dinosaurs have been discovered at Early Jurassic sites worldwide, including the Rocky Mountains, New England, and eastern Europe. Some of these tracks might belong to Dilophosaurus.
Finding Fossils
Much of what we know about Dilophosaurus stems from findings on Navajo Nation land. In 1940, Jesse Williams, a Navajo man, became the first recorded individual to discover a Dilophosaurus skeleton.
Two years later, a team of visiting scientists reached out to Williams. He led them to a Jurassic-era site where three Dilophosaurus fossils were uncovered.
Today, several specimens of this dinosaur — legally owned by the Navajo Nation — are held in trust at the University of California Museum of Paleontology.
Samuel P. Welles enjoyed a long and productive career there until his passing in 1997. As mentioned earlier, Welles named Dilophosaurus and was among the scientists guided by Jesse Williams in 1942.
Welles demonstrated that one can enjoy a dinosaur film while acknowledging its scientific flaws. After "Jurassic Park" premiered in 1993, he openly addressed the inaccuracies surrounding Dilophosaurus.
Despite this, Welles publicly stated, "I thoroughly enjoyed the film and was delighted to see Dilophosaurus gain international fame as a star."
In 2017, Connecticut designated Dilophosaurus as its official state dinosaur. Early Jurassic-era tracks from an unidentified carnivorous dinosaur have been discovered in the state, and it's possible that Dilophosaurus (or a similar species) was responsible.