You might not think a paleontologist looking for 66-million-year-old fossils would need to ask a rancher about his great-grandmother's job in the Wyoming badlands. But that's what Paul Sereno, a paleontologist at the University of Chicago, did when he was trying to track down a historic site where a famous dinosaur mummy was found in 1908.
Sereno's work, published in the journal Science, brings new clarity about the appearance of the duck-billed Edmontosaurus annectens, a massive herbivore from the Cretaceous period. Sereno and his team's painstaking work reveals the dinosaur's hooves and spiky tail in exquisite detail. They studied how a fragile clay template can create dinosaur "mummies."
But first they had to find them.
"It involved sleuthing archives and finding photographs from these original excavations that no one knew of, and then also talking to ranchers," Sereno says of the research.
Looking for a post office
Sereno was hunting for the spot where the famed collector Charles Sternberg discovered a dinosaur mummy in the rough terrain of eastern Wyoming. He managed to find historical photos and a note from Sternberg recounting his path to the site, back in the era of horse-drawn carriages.
There were references to Warren, Wyo., — a town that, Sereno says, "doesn't exist on any map." So, he asked around at nearby ranches.
"One of the ranchers had a great-grandmother that was the postmaster of Warren, Wyoming," Sereno says. In those days, the post office was on a ranch, he adds.
"And from that, I can calculate a distance to one of the mummies that were found in 1908," Sereno says.
The area has come to be known as "the mummy zone," where a very thick layer of river sand captured dinosaurs' bodies and preserved valuable information about them. As technicians removed grains of sand from the Edmontosaurus specimens, Sereno was fascinated by what they found.
"A mummy is actually a mask of the body, very thin, like the clay you'd put on your face to clean out your pores," he says of their specimens. "And that's what's trapped in the sediment, and not a replacement of the actual skin."
Vital details about the large dinosaur were captured in fragile clay templates, just one-hundredth of an inch thick.
"For once, we know what a large dinosaur looks like from head to toe," Sereno says. "We've got the bill at the front end, the hooves ... and samples of everything in between, including the crest on the back, the spikes on the tail. We know it, and you could depict it, and it's accurate."
"With one exception," he adds. "We don't know the color."
The two specimens include an adult nicknamed "Ed Sr." and a late juvenile dubbed "Ed Jr." — "the only juvenile dinosaur mummy ever discovered," according to the university.
"The feet are beautiful"
Sereno's study quickly caught the eye of other experts on the duckbill dinosaur, including Clint Boyd, the paleontology program manager for the North Dakota Geological Survey. His agency has its own Edmontosaurus specimen ("Dakota the Dinosaur Mummy"), so I asked Boyd what he thinks of Sereno's study.
"The feet are beautiful," Boyd says, adding that the new study jibes with much of his agency's work.
Both Boyd and Sereno say that some of the terminology in their field could confuse a layperson. They stress that these mummies are nothing like Egyptian mummies, for instance. And when they say Edmontosaurus had hooves, they warn not to think of a horse hoof.
"What they're talking about is a hoof like what you see on like a rhino, which absolutely that's what it looks like," Boyd says, describing a prominent nail in the front of fleshy pads.
Boyd says that while Sereno's specimens are different from what he and his colleagues are working on, the new paper resolves important questions and will help drive new research.
"It's a very thorough study, which is great," Boyd says. "We needed a very good baseline for understanding at least one set of dinosaur mummies in order to then have a reference point to start comparing back to other specimens. So this has been a very long-needed addition to the science."
Kindling an interest in paleontology
This isn't Sereno's first dinosaur rodeo. He's made big discoveries before. His email address doesn't even use his name; instead, it just says, "dinosaur."
The mummy study closes a meaningful loop in Sereno's own life. He notes that the prize specimen that sparked his search, unearthed back in 1908, sits in the American Museum of Natural History in New York — and it was a visit to that spot, decades ago, that made a huge impact on a Sereno.
"That's when I decided to be a paleontologist," he says of standing next to that exhibit. "Little did I know my career would end up taking me back to where that mummy was discovered by Charles Sternberg more than a century ago."
Sereno has a message for young fans of dinosaurs and paleontology: "If you're an enthused kid, thinking, maybe we found everything. No, we have not."
Plenty of work remains to make new discoveries and solve more mysteries about how dinosaurs lived, he says.
"For the next two generations, we're going to be finding more things about the deep past and about dinosaurs and other creatures than ever," Sereno says.
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