Some paleontologists travel far and wide to seek new fossils — to the desert Southwest of the United States, remote regions of China or the farthest tip of Argentina. University of Pennslyvania student Jack Stack, on the other hand, made his first paleontological discoveries much closer to home.

At home, in fact.

“My family lives on a long, gravel driveway,” says Stack, a junior at Penn who hails from Ithaca, a small town nestled in the middle of the “mitten” of Michigan’s Lower Peninsula. “When I played outside as a kid, I started finding bits of invertebrates, corals and shells in the gravel that was dumped there.”

At 9 or 10 years old, it wasn’t clear that such finds would amount to more than unique show-and-tell props. But for Stack they became the spark of much more. A decade later, paleontology is Stack’s career ambition. He’s published articles and a book. He’s initiated and led several research projects. He’s given poster presentations and, unusual for an undergraduate, two talks at leading scientific conferences. And he’s an active member of the lab of Lauren Sallan, Penn’s Martin Meyerson Assistant Professor in Interdisciplinary Studies in the School of Arts and Sciences, all while balancing a full courseload.

“He is really dedicated to his path,” says Sallan. “Most undergraduates, you bring them into the lab and they don’t necessarily know what they’re interested in, and they certainly don’t lead their own projects in freshman and sophomore years. He has the direction and drive of an advanced graduate student.”

It wasn’t long after those driveway discoveries that Stack started keeping an eye out for fossils wherever he went. A game of horseshoes at a family reunion dissolved into a fossil-hunting mission after he discovered “a beautiful coral” on the underside of the rock he was using to hammer stakes. He identified a new fossil site near the shores of Lake Michigan while on a bike ride at his grandmother’s house. On weekends, his supportive parents spent long days driving him up and down the state to collect.

In middle school, he began writing articles about specimens he’d found for publication in paleontology newsletters. He reached out to amateur and professional paleontologists, many of whom enthusiastically shared their knowledge with Stack, encouraging him in his pursuits. Murray Borrello, a geologist and instructor at Alma College, near where Stack grew up, became a mentor.

“He was a role model,” Stack says. “He helped me transition from a child’s interest into doing science.”

While still in the eighth grade, Stack began work on a book, Fossil Hunting in the Great Lakes State: An Amateur’s Guide to Fossil Hunting in Michigan. He completed and self-published it when he was 16. He continues to do book signings at festivals when he’s back in Michigan.

“It’s amazing to me how many people are interested in science,” says Stack. “And, no offense to chemistry or physics or mathematics, but paleontology is a great way to draw people in. Not many kids know all the polyatomic ions, but there are 5-year-olds out there that know the names of Tyrannosaurus rex and all these other dinosaurs and know a lot of information about them, too.”

When he was about 15, Stack and his family were attending a talk at Central Michigan University. In chatting with the speaker afterwards, Stack’s father mentioned his son’s interest in fossils.

“He said, there’s a new person at the University of Michigan who is doing research on fish fossils; you should talk to her,” says Stack.

That researcher was paleobiologist Lauren Sallan, who joined Penn’s faculty in 2014. When Stack emailed to introduce himself and share information about his fossil collections and research, she promptly invited him to conduct a research project with her.

“It was pretty surprising that a professor at the University of Michigan wanted to do a project with a high school student,” says Stack, “but that was almost five years ago and we’ve been working together ever since.”

“It was really impressive to meet a high schooler who was that much of a self-starter,” Sallan says. 

That first project involved comparing fossil fishes in Michigan from the Devonian Period with with those found in Ohio and New York. The three areas were well-connected, Stack says, and Michigan in particular was home to a vast array of now-fossilized sealife. Three hundred eighty million years ago, the Midwestern state was covered by a shallow, tropical saltwater sea.

“The fossil assemblage in Michigan is amazing,” Stack says. “You have lots of corals and shells, and you also have giant armored fish. You’ll find something from the size of a fish you’d keep in a tank at home to specimens that are over eight feet long. They look kind of like you took a shark and gave it a bear trap for a mouth.”

In the midst of their work on this project, Sallan told Stack she was moving to Penn, and that she wanted him to go there too.

“That’s how I found out about Penn,” Stack says. “I visited and I loved it, but the real reason I came here was to work with Dr. Sallan.”

Since arriving in Philadelphia, Stack has embarked on other research projects with Sallan, while pursuing his degree in earth science with a concentration in paleobiology. In one, he redescribed an ancient long-nosed fish species called Tanyrhinichthys. Originally believed to be a sleek-bodied ambush predator like a pike, more recently discovered fossils suggest that it may have actually been a slow-swimming bottom feeder, akin to a sturgeon.

This past summer, he presented his findings in a talk before an international gathering of fish paleontologists in Chęciny, Poland. He was the only undergraduate in attendance.

“I’d never given a talk before so that was a stressful few weeks preparing for that,” says Stack. “But it was really neat meeting all the people in my field. And it was a beautiful place to visit.”

Stack has an impressive resume for a 20-year-old. He has received a research grant from the Paleontological Society and has twice been chosen to serve as a Paleontological Society Student Ambassador at the Geological Society of America conference, where he also gave a well-received talk last month. He has a paper submitted, another one he’s preparing, and he is embarking on a new research project.

But he also acknowledges he has a lot to learn and is grateful to Sallan for her mentorship.

“Dr. Sallan has always been very patient,” Stack says. “She’s definitely a role model for what I’d like to be: a researcher, a teacher. I don’t know how I managed to bumble into someone as expert as her when I was just in high school, but, as I like to acknowledge, I’m the luckiest person on the planet.”

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