Dilophosaurus, a dinosaur made famous by Jurassic Park that lived 183 million years ago, was ‘bigger and more powerful’ than the movie made it appear, study shows.
Researchers from the University of Texas studied Dilophosaurus fossils to better understand this ‘pop culture dinosaur’ and paint a true picture of its size.
In Jurassic Park the beast was depicted as a small lizard-like, venom-spitting dinosaur with a rattling frill around its neck and two paddle-like crests on its head.
Until now very little was actually known about the actual Dilophosaurus, giving filmmakers and storytellers more licence to ‘use their imagination’.
The Texas team discovered that Dilophosaurus was far from the ‘small lizard’ seen in Jurassic park, it was the largest land animal of its time, reaching up to 20ft.
Hollywood made the Dilophosaurus famous, depicting it as almost adorable little creature with a hidden, deadly twist. But a new study shows that it was a lot bigger and more powerful than scientists, or movie makers, previously thought
This is the depiction of Dilophosaurus as seen in the 1993 Steven Spielberg movie Jurassic Park but it has been proved to be wrong, including the bright thrills around its neck
Dilophosaurus lived 183 million years ago during the Early Jurassic and ‘had a lot in common’ with modern birds, including air sacks in its bones.
‘It’s pretty much the best, worst-known dinosaur,’ said lead author Adam Marsh. ‘Until this study, nobody knew what Dilophosaurus looked like or how it evolved.’
Seeking answers to these questions, Marsh conducted an analysis of the five most-complete Dilophosaurus specimens so far discovered around the world.
The analysis is co-authored by Timothy Rowe from the University of Texas, who discovered two of the five Dilophosaurus specimens that were studied by Marsh.
The study adds clarity to a muddled record dating back to the first Dilophosaurus fossil to be discovered – that specimen set the standard for future discoveries.
That fossil was rebuilt with plaster, but the 1954 paper describing the find isn’t clear about what was reconstructed or the decisions made in the reconstruction.
Scientists have found evidence that the Dilophosaurus’ skull served as scaffolding for powerful jaw muscles, shattering the image of the dinosaur as more fragile and svelte that has been promoted in scientific literature and popular culture
Peter Makovicky, a palaeontologist from the University of Minnesota not involved in the study, said this made discovering the true nature of the dinosaur difficult.
Early descriptions characterise the dinosaur as having a fragile crest and weak jaws, a description that influenced the depiction of Dilophosaurus in the ‘Jurassic Park’ book and movie as a svelte dinosaur that subdued its prey with venom.
In the movie the dinosaur is also shown as being able to reveal a rattling neck frill when confronting prey.
Marsh found no evidence for the rattling frill around its neck or signs of venom, adding that they were purely constructs of the Jurassic Park book and movie.
Marsh spent seven years looking at the three most complete Dilophosaurus skeletons and other more recently discovered remains to pain an accurate picture.
His evidence suggests the dinosaur was almost the opposite of what Jurassic Park showed – with jawbones serving as scaffolding for powerful muscles and signs the creature was a giant beast, reaching up to 20ft in length.
It would have been about half the size of a fully grown T. Rex and weighed up to three quarters of a ton – so it could have taken on very large prey.
‘Dilophosaurus is clearly built for being a big macropredator,’ Marsh told National Geographic. ‘It’s a large-bodied animal that was built for eating other animals.’
He also found that some bones were mottled with air pockets, which would have helped reinforce the skeleton, including its dual crest.
‘They’re kind of like bubble wrap – the bone is protected and strengthened,’ he said.
These air sacs are not unique to Dilophosaurus, it is something they have in common with modern birds and the world’s most massive dinosaurs.
In both cases, the air sacs lighten the load, which helped big dinosaurs manage their bulky bodies and also allow birds take to the skies.
Many birds use the air sacs to perform other functions, from inflating stretchy areas of skin during mating rituals, to creating booming calls and dispersing heat.
The intricate array of air pockets and ducts that extend from Dilophosaurus’ sinus cavity into its crests means that the dinosaur may have been able to perform similar feats with its headgear.
That headgear is one feature Jurassic Park did get right, according to Marsh. He said it did have a double crest across the top of its snout that was a ‘display feature’.
The right hind leg of Dilophosaurus. The dinosaur lived 183 million years ago during the Early Jurassic and ‘had a lot in common’ with modern birds, including air sacks in its bones
‘It has those two thin bony crests running along the top of its skull, basically from the nostril and back over the eye socket,’ Makovicky told National Geographic.
To learn more about how the fossils compared with one another, Marsh recorded hundreds of anatomical characteristics of each fossil.
He then used an algorithm to see how the specimens compared with the first fossil – which confirmed that they were indeed all Dilophosaurus.
The algorithm also revealed that there’s a significant evolutionary gap between Dilophosaurus and its closest dinosaur relatives, which indicates there are probably many other relatives yet to be discovered.
The revised Dilophosaurus record will help paleontologists better identify specimens going forward and Marsh said that the research is already being put into action.
In the midst of his analysis, he discovered that a small braincase in the Jackson School’s collections belonged to a Dilophosaurus.
‘We realized that it wasn’t a new type of dinosaur, but a juvenile Dilophosaurus, which is really cool,’ Marsh said.
The findings were published in the Journal of Paleontology.