Discoveries in dino country

Finding the Flyby

How did the team know there were fossils here in the first place? The journey began back in 2019, when a Montana rancher flew his plane over the property he leases from the Bureau of Land Management. While checking on his cattle from the air, he noticed something peculiar poking out of a hillside.

The rancher told Wilson Mantilla, his go-to contact about fossil discoveries on his land for nearly a decade. Experts would eventually confirm it was the horn of a Triceratops (a “trike,” in paleontology slang) — a large herbivore that roamed the Late Cretaceous landscape alongside its foe, the T. rex, until the mass-extinction event that brought an end to the age of the dinosaurs. In the rancher’s honor, Wilson Mantilla dubbed it the Flyby Trike.

After being delayed a year by the pandemic, Wilson Mantilla and Abrams cleared their calendars for July 2021 and pulled together a team of volunteers and students from the UW and other universities. K–12 educators from the Burke’s annual DIG Field School program would also help with the excavation, bringing their firsthand experience back to students in Washington and across the country.

Just a few hundred yards from the trike site, prospectors with permission to scout there followed trails of “float” — shards of fossilized tendon and bone that drift down the hill — to their origins like breadcrumbs, finding fossils of two more dinosaurs. And six miles from the main cluster, a prospector had helped Wilson Mantilla find yet another fossil with great promise.

The dig was on.

Unearthing clues

The possibility of a new discovery adds a blast of excitement to what is already a peak experience for second-year transfer student Zeke Augustine, ’23. He has just returned from the smaller site, where he helped excavate what could be a new species or might be a “chicken from hell,” paleontologists’ nickname for the rare Anzu wyliei — an 11-foot-long theropod estimated to have weighed up to 650 pounds. The vertebrae, says Wilson Mantilla, are spot-on for the group oviraptorosaurs, and the fossil is similar in size to the genus Anzu. They’ll learn more as it’s studied back in the Fossil Preparation Lab, but Augustine, a lifelong dinosaur enthusiast, helped secure the clues: a pelvis, vertebrae, limbs and a four-inch claw that Wilson Mantilla describes as “visceral.”

Today Augustine is back with the larger group, focused on a more common hadrosaur — but digging up any dinosaur is the stuff of paleontology dreams.

These aren’t the fossils you see in the movies, standing out a distinct white against the dirt. Fossils form when dissolved minerals seep into and replace organic material, crystallizing in the shape of the original bones. That’s why you don’t use high-tech equipment to scan the ground, explains Wilson Mantilla — it would be like trying to discern rock from rock. You have to dig, and do it carefully.

What’s more, fossils are rarely found complete and intact — they’re often scattered by scavengers, tumbled in water or worn apart in the earth. That’s the case with the hadrosaur that Augustine and Eddie Armstrong, ’20, are working on today, along with volunteer Vince Bruscas Sr., who goes on dinosaur digs every year with his wife and son.

The team has uncovered the hadrosaur’s hips and legs, and much of the fossil has already been encased in plaster for protection and safe transport back to the Burke. Augustine and Armstrong are down on all fours carefully unearthing several vertebrae, which are distinctly smooth against the jumbled mudstone.

Later in the day, volunteers help roll the other plaster-encased theropod fossil — a hipbone of an ostrich-size animal — onto a pallet, which the rancher then winches up the hill with his tractor and loads into Bruscas’ pickup truck for safe transport back to the Burke.

The future of the past

After a month of digging, it becomes obvious to Abrams and Wilson Mantilla: The dig team won’t be able to excavate the Triceratops this year. The more they expand the perimeter around it, the more fossil they find. There’s plenty left to be unearthed, and they’re running out of time. So, to protect it from harsh weather over the winter, they cover it in insulating plaster and shovel mudstone on top.

While Wilson Mantilla and Abrams look forward to returning next year — especially since the Burke Museum doesn’t yet have a Triceratops skull, only a cast — they’re thrilled about what their team uncovered. The somewhat common hadrosaur and theropod, and fossilized seedpods and amber, will add to their knowledge of the area’s biodiversity at the end of the age of dinosaurs. And the theropod from the other dig site, be it a rare Anzu wyliei or a new species within the genus, will shine new light on the diverse ecosystem of Hell Creek.

“Each fossil we collect helps sharpen our views of the last dinosaur-dominated ecosystems and the first mammal-dominated ecosystems,” says Wilson Mantilla, who’s interested in how mammals rose to prominence as dinosaurs were largely erased from Earth. “With these, we can better understand the fragility, collapse and assembly of ecosystems.”

Ruiz, Yao, Augustine and Armstrong return with something of their own: The experience of a real-life field dig to complement their classroom learning and help launch them toward their dreams of becoming paleontologists.

Someday, they too could help contribute to our knowledge of what once was and what might be. In fact, Wilson Mantilla and Abrams would say, they already have.

“This is not just Kelsie or me doing something,” says Wilson Mantilla. “It’s a full team, and every player has an important role.”

Photography by Dana Brooks, ’21, and Dennis Wise. All activity and photography followed the COVID-19 safety protocols at the time.

Originally published November 2021