Nine miles north of the University of Texas at Austin, in a three-story, gray concrete building on the satellite J.J. Pickle Research Campus, there is an archive. In the archive there is a cabinet, and in the cabinet, there is a dinosaur leg. The skeletal limb is posed in a crouch, as if its owner were still lurking in an early Jurassic thicket. Once clothed in meat and muscle, the birdlike toes—articulated, curled—are smooth and cool to the touch.
The leg belongs to a young adult Dilophosaurus, a large, double-crested predatory dinosaur from 183 million years ago. Made famous by its frilled, venom-spitting incarnation in Jurassic Park, Dilophosaurus has been a staple of dinosaur books and video games for decades. But despite its fame, paleontologists knew surprisingly little about it. Working with fragmentary fossils and unclear research, they long considered the species to be weak-jawed and primitive. This week, a new paper by UT alum Adam Marsh and colleagues—drawing partially on “gorgeous” specimens like the one at UT—has offered a fresh look at the animal, revealing it to be far more formidable than previously understood. Their research hasn’t just clarified aspects of a scientifically elusive dinosaur; it’s also provided a glimpse into how heavily our understanding of the past depends on who’s telling the story.
“It’s everywhere in pop culture, it’s everywhere when you’re looking at comparative anatomy of early dinosaurs,” Marsh says. “But nobody really knew what it looked like. It’s the best-known worst-known dinosaur.”
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In 1940, Jesse Williams, a member of the Navajo Nation, found weathered bones poking from the red ground near Tuba City on tribal lands in Arizona. News of the find spread to Richard Curry, operator of a trading post, who in turn alerted University of California at Berkeley paleontologist Sam Welles to excavate the site. (Whether or not Welles had a permit to do so is a subject of some dispute: Berkeley maintains that he did, while Navajo leaders argued in 1998 that the bones had been taken without permission.) The remains, Welles realized, belonged to a species of twenty-foot-long carnivore, a preview of later, immense dinosaurian hunters like Tyrannosaurus rex.
In 1984, Welles formally named the beast Dilophosaurus, “two-crested lizard,” after the paired paddle-shaped crests on its head. He described the animal as having particularly fragile jaws and crests, and speculated that a groove in the upper jaw—now known likely to be a simple joint in the bone—might have housed a sac of venom. According to Kevin Padian, a paleontologist at Berkeley, this idea was enthusiastically picked up by Jurassic Park author Michael Crichton, who depicted the animal as a large, venomous predator. Steven Spielberg’s film shrank Dilophosaurus considerably and added an expanding, rattling frill based on the modern frilled lizard. “[The poison idea] gave Dilophosaurus a new life,” Padian says, “but unfortunately it gave a wrong impression.”
Welles’s publication had given off a few other false impressions as well. His approach was a bit archaic even at the time, according to Marsh: “The 1984 volume that didn’t always make clear what anatomy from the Berkeley specimens was real and what was reconstructed with plaster.” Researchers referencing the original paper did so without knowing how much of its anatomical description was shaky. The result was a mirage: an animal that seemed well-known, but was actually the subject of tremendous uncertainty.
That’s pretty much how things stayed until 2013, when Marsh began working on his master’s degree at the University of Texas. He spent his days in the extensive vertebrate paleontology collections of the Jackson School Museum of Earth History, a five-thousand-square-foot, barely climate-controlled warehouse containing more than a million fossils. (The fossil preparation labs and offices, unlike the rest of the building, are mercifully air-conditioned.) Originally he was there to study Sarahsaurus, a small, early relative of animals like Brontosaurus found on Navajo Nation land. But the white metal cabinets also held ten shelves worth of Dilophosaurus bones, and these soon drew his interest.
The remains—from two individuals collected by Timothy Rowe, an eventual co-author on the new paper—were gorgeously well preserved, Marsh says. He could still see every detail of the 183-million-year-old bones. There was a delicate little braincase, from a young animal; a lower jaw, with teeth packed into the sockets like a clip of bullets; a row of articulated, curved vertebrae, occasional curls of bright red iron encrusting the bones; and that long, crouching leg. “I was interacting with those bones in the collection on a daily basis,” Marsh says. He was struck by how well preserved they were, showing anatomical detail absent from the Berkeley specimens that had shaped scientific understanding of the dinosaur. “I felt that Dilophosaurus was in a big need for a comprehensive overhaul.”
Marsh, now a doctoral student and paleontologist at the Petrified Forest National Park, got to work. In addition to carefully analyzing the materials held in Texas, he spent a semester at Berkeley with Padian in 2015, scrutinizing Welles’s original specimens and building up a data set of hundreds of anatomical characteristics of each fossil. “I basically lived and breathed Dilophosaurus for several months,” he says. Far from the weak-jawed predator Welles had originally described, Marsh found that the preserved jawbones indicated the presence of powerful muscles, and the crests were likely quite tough. In addition, some of the bones showed signs of holding air sacks, an evolutionary innovation that became common in later dinosaurs, including modern birds. Air sacks lighten and strengthen the skeleton, Marsh says, and help birds breathe more efficiently. That same network of air ducts also extended from the skull’s sinus cavity into its crests, possibly helping the animal dispel heat, or providing the basis for extravagant soft tissue, like the inflating sacks some birds use for mating displays. Taken together, the five skeletons suggested that rather than the compact “crest with claws” depicted by Jurassic Park, Dilophosaurus was an elegant and rather streamlined creature: long-tailed, long-legged, and long-jawed. (No frills, you might say.)
Marsh also dived into the question of how Dilophosaurus was related to other dinosaurs. Pinning down the family relationships of the earliest predatory dinosaurs has long been tricky, and Dilophosaurus has surfed along on competing waves of taxonomic argument, with researchers trying to place it as an ancestor of this or that family of large predatory dinosaurs. But Marsh’s research suggests that rather than serving as an ancestor to later big predatory dinosaurs, Dilophosaurus belonged to its own distinct family, with a distinct evolutionary gap between it and its closest relatives.
“This research strongly suggests that the late Triassic–early Jurassic was a time of radical and bizarre evolutionary diversification and experimentation,” says Brian Engh, a paleoartist, puppeteer, and filmmaker who provided illustrations for the paper. “Dilophosaurus … is just one of myriad bizarre forms that existed for millions of years in the shadows of the fragmentary fossil record.”
The new “nuts and bolts” analysis doesn’t solve everything about Dilophosaurus, Marsh says. It simply lays out a foundation for new and more precise questions, such as how the animal grew, its place in food webs, its evolutionary relationships. Future researchers will likely be using the anatomical road maps that Marsh and his colleagues have laid out to dig into these questions for years to come.
But Dilophosaurus isn’t just the sum of its bones. Like all dinosaurs, it’s a cultural artifact, too. Paleontology, as with many disciplines of natural history, has a troubled colonial history. Until the early twentieth century, expeditions often stole artifacts from tribal lands and shipped them off to distant museums. These days, Dilophosaurus is emblematic of a different model of working relationship: like all fossils legally collected on the Navajo Nation since the 1950s, the bones belong to the tribe. Museums and labs, including at Berkeley and UT, hold them in trust. These fossils can be recalled any time the Nation wishes. (Representatives of the Navajo Nation declined to comment for this story.)
Today, fossilized footprints believed to belong to Dilophosaurus are a local tourist attraction on the Navajo Nation outside of Tuba City, and according to Farina King—a Navajo scholar of indigenous history at Northeastern State University who was born not far from the Dilophosaurus site—have long been a valued part of the nation’s relationship with the past. Navajo caretakers have devoted themselves to protecting the land from vandals, King says, including volunteering to stand guard all night to protect the remains. When Marsh and his crew returned to the nation as part of a Navajo-sanctioned effort to relocate Welles’s original excavation site—the exact location had never been properly recorded—the teenager leading the footprint tour turned out to be a descendent of Jesse Williams, the original discoverer of Dilophosaurus. Another relative led them to the spot on the ground where Welles had pulled up the bones.
“There have been indigenous people who’ve lived on these lands for time immemorial and have developed our own epistemology, our own ways of knowing,” King says. “The families that have lived in Moenave, between Tuba City and Cameron City, Arizona … they take stewardship of these fossil remains very seriously.”
To help keep the research accessible to people on the Navajo Nation, Marsh says, The Journal of Paleontology agreed to waive its usual fee, making the paper free online for anyone who wants to read it. Marsh is also planning to send hard copies to tour guides and museum staff on the nation. “It’s cool to think of Dilophosaurus as a kind of Navajo Nation celebrity, and a celebrity even on the nation when people are talking about these tracks,” Marsh says.
The main collections of the Jackson School Museum of Earth History sprawl across two floors. The smaller material—such as the fragmentary leg of Dilophosaurus—is held in fifteen long rows of cabinets. To see the larger material, Matthew A. Brown, preparator and director of museum operations, took me down to the basement. This cool, low-ceilinged room is a labyrinth of shelves stocked with strange shapes: horns, eyeholes, overturned jaws of mammoths and mastodons and ground sloths, the great head of a giant crocodilian still half in its matrix, immense titanosaur tibias, bones shaped and sculpted out of rock by many collectors’ hands.
Dilophosaurus, Brown says, is also a reminder of something else: how dependent our understanding of the past is on the people who are looking at it. Preparators aren’t just sitting down with a block of stone and pulling a bone from it. Instead, they often make decisions about what to preserve, what to reconstruct, and how to reconstruct it. It’s become increasingly clear over the years that skin impressions and other soft tissue remains are more common than previously assumed; earlier preparators simply didn’t think to look for them, or failed to recognize them in their rush to get at the bones. “A lot of the work I do is looking into how we physically shape the bone,” Brown says. “We look at the things on the shelf as kind of a voucher for these animals, but paleontologists tend to take for granted that [the bones on the shelf] are representative of the organism. But this is also an anthropogenic product. This is also something we’ve created and shaped.”
It’s easy to dismiss the original plaster-and-bone reconstructions created by Welles and his colleagues as wrong. But that misses the interesting thing about them: that Welles was trying to reconstruct an animal nobody had ever seen before. The problem wasn’t that he was wrong: the problem was that it took a while for anybody to check. Even now, understanding Dilophosaurus, like all dinosaurs, is as much art as science, and like the best art, it contains elements that can never be resolved.