by Bethany Augliere Tuesday, June 5, 2018
When roads are built in fossil-rich states, paleontologists sometimes follow the trucks and bulldozers to make sure that the buried treasures that construction crews occasionally uncover — namely, remnants of ancient animals and plants — get out of the ground safely and into a museum to be cataloged and studied.
The first state to establish such a highway paleontology program, in 1960, was Nebraska, where, today, the role of state highway paleontologist is held by Shane Tucker.
A native of the state, Tucker grew up stashing rocks and clamshells into his dad’s tackle box during fishing trips. “I wanted to be a paleontologist since I was a kid,” Tucker says. “It sounds kind of goofy, but I am living out my dream.”
Tucker earned a bachelor of science in geology with minors in biology and math at the University of Nebraska–Lincoln in 1997. While in college, he worked as an intern at Ashfall Fossil Beds State Historical Park in northeastern Nebraska. After graduation, he continued at the university, earning a master’s degree in geosciences with an emphasis in vertebrate paleontology.
In 2000, Tucker started working as a preparator for the Nebraska Highway Paleontology Program, which is a collaboration between the University of Nebraska State Museum, where Tucker is based, and the Nebraska Department of Transportation. Seven years later, he assumed the role of state highway paleontologist. During the Nebraska program’s 58 years, fossils ranging in age from 20,000 years to 290 million years have been recovered in 91 of the 93 counties in the state. Over the years, Tucker has helped recover specimens of primitive horses, camels, rhinoceroses and even marine reptiles like mosasaurs.
Tucker recently spoke with EARTH contributing writer Bethany Augliere about how he got started as a paleontologist, some of his exciting discoveries, and what he enjoys about Nebraska rocks.
BA: What exactly does a highway paleontologist do?
ST: I review road construction projects that are going on around the state, and analyze potential impacts on fossil resources. Based on the rock units that will be exposed in an area, we determine which projects are more likely to produce fossils. Then we go out and monitor those projects. If there are any fossils that are uncovered, we’ll excavate them, bring them back, and then curate them into the paleontology research collection here at the museum. Nebraska is extremely rich in fossil resources, and our natural history museum has more than a million-and-a-half vertebrate fossils from throughout the state.
We often walk behind equipment like scrapers or bulldozers. If we find bones, we’ll flag down a worker or get in touch with a project manager. Then the construction just shifts a little while we do exploration. The good thing is it doesn’t stop or get in the way of the road construction.
BA: What kinds of fossils do you find in Nebraska?
ST: There are fossil invertebrates and vertebrates from the Paleozoic, Mesozoic and Cenozoic eras. Depending on where you go in the state, you’ll find different ages of fossils. In the far southeastern portion of the state are the oldest rocks, between 290 million and 320 million years old.
There’s a pass in the eastern third of the state that has exposures of rocks from 100 million to 70 million years ago, when Nebraska was mostly covered by oceans. The fossils we find there are from the end of the Age of Dinosaurs, including fossil fish, invertebrates, mosasaurs and plesiosaurs.
What Nebraska is really known for, though, are its mammals. Our fossil mammalian record is second to none, and many museums from across the country have collected here over the years. We have things like four-tusked elephants, rhinos, three-toed horses, lions, horned rodents that are like prairie dogs with horns on their noses, and dogs that had bone-crushing jaws.
BA: You have to be able to recognize many fossils for this job; what makes you successful in this position?
ST: Lots of on-the-job experience, in addition to the training as an undergraduate and graduate student. The two internships I did at Ashfall Fossil Beds really helped me, as did my mentors who had decades of experience studying Nebraska geology and paleontology.
Much of the background research for individual highway construction projects is done in the office. Prior to monitoring a project, we know which rock layers will be impacted and the fauna from this unit. There are features on individual bones that identify them as being from a horse, a rhino, a camel or a bison, for example. The more detailed identifications down to species level are done in the paleontology research collections at the museum, by curators, students, outside researchers and myself.
BA: I can’t say I’d ever heard of a highway paleontologist before meeting you. Is this what you thought you’d be doing?
ST: No, my plan originally was to work toward a doctorate, do research and teach as a professor. Then I saw how difficult it was to get a position in paleontology and I had this opportunity to work at the museum that I had visited so much as a kid. I thought, “I get to study the rocks in Nebraska, I get to study the fossils, I’m part of our natural history museum, and I’m being paid.” All that made the opportunity worth it. I absolutely feel lucky.
BA: What about paleontology, and your job specifically, excites you?
ST: First, it’s the sense of discovery. When I’m out in the field, for example, I could work all day shoveling sand and not find anything. But, the next scrape could expose a jawbone that I’m the first person to ever see, and it might be millions of years old. That’s extremely exciting.
I also get to interact with the public, which is exciting because everybody has a different story. Everybody has found something. I’ve seen people’s eyes light up like a kid’s when you identify something they’ve found that’s millions of years old.
I also get to be outside and see beautiful parts of the state. People think Nebraska is flat because they travel on Interstate 80. We have buttes, 150-meter-tall sand hills, and deep river valleys. We have beautiful sunrises and sunsets in four different seasons, and I get to see that. A lot of people don’t know this, but the largest sand sea in the Western Hemisphere — the Sand Hills — is in Nebraska, it’s just covered with grass. That’s why I love the job.
BA: What did you study for your master’s research?
ST: It was actually a highway construction project, in Keya Paha County in north-central Nebraska, called the Rick Irwin Site. The museum and my advisor knew of this site but its age was unknown — the goal of my project was to narrow down the age.
Some of the bones discovered by Rick Irwin, a state highway employee, were from taxa that were extremely rare in the Niobrara River Valley. There are hundreds of fossil localities [represented] in our museum collection, as well as at the American Museum of Natural History collection, from time intervals older than 9 million years ago and younger than 3 million years ago. The rare fossils suggested that the [Irwin] site filled a portion of this missing time slice. By using the known temporal ranges of certain carnivore and rodent taxa, we determined the age of the site to be between 6 million and 6.6 million years old. This site is one of the most diverse spots for carnivore faunas of its age in North America. We’ve identified 17 different carnivore taxa.
BA: A common misperception about paleontologists is that they all dig up dinosaurs. Nebraska doesn’t have many dinosaur fossils. Did you originally want to study dinosaurs?
ST: I liked dinosaurs as a kid and had dinosaur toys. “Jurassic Park” had just come out after I graduated high school, and I was thinking I was going to study dinosaurs in Nebraska in college.
When I had the chance to do an independent study project with Mike Voorhies, the curator of vertebrate paleontology at the museum and a geologist at the University of Nebraska, I wanted it to be on dinosaurs. He took me to the museum and showed me a shelf with the two dinosaur fossils from Nebraska. One is a broken limb and the other is a small section of a tooth. And I thought, “Well, that is pretty disappointing.”
Then he showed me the mammals. He showed me a full skeleton of a rhino with every bone. The hook, line and sinker was a saber-toothed cat skull. I thought, “This is so much cooler than the dinosaur fossils!”
BA: What is the coolest fossil you have found?
ST: That’s hard to say; there have been a lot. I was working on a project in the Wildcat Hills in the western region of the state, and the last fossil we found before we finished the project was the skull of a slingshot-horned deer called Prosynthetoceras. It isn’t a true deer but an extinct family that resembled deer. That’s the only skull from that genus that I’m aware of that’s ever been found in Nebraska — it’s extremely rare.
The crazy part is that I’d first found the fossil two days before. The animal has a horn that is kind of curved like a rib, so I thought I’d just found a rib. It wasn’t until I came back to the site, dug more and saw the eye socket that it popped into my head that this was the skull of a slingshot-horned deer. I was so excited, I was visibly shaking. It’s on display now at the museum.
When we collected it, we put it in a plaster field jacket and took a lot of extra sand [from around the skull], so we didn’t have anything fall out when flipping the jacket. This could happen in loose sand if you aren’t careful. Back at the lab, we realized there were about six other partial skulls and jaws in the same field jacket — including one from a primitive three-toed horse called Archaeohippus.
BA: Is there a particular fossil you are hoping to find someday?
ST: In the old rocks of the far southeast corner of Nebraska, we have fossil lungfish. Today, they’re found in Africa, South America and Australia, so you wouldn’t necessarily expect them to be in Nebraska. But when these fish were alive, Nebraska was part of the supercontinent Pangea. Geologists collected lungfish from one site during a past road project, and our museum went back and collected a few more, but I’ve never encountered any of those. There’s just a lot of cool stuff here; Nebraska is a great state for a paleontologist.
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