BY HANNAH LAZO
COLUMBIA – Not many people can say they uncovered their life’s passion in their own backyard, but for Tara Selly, that’s exactly what happened. Selly said she can remember burying plastic dinosaurs in her sandbox and using a spoon to unearth them when she was just 4 years old.
Fast-forward a couple of decades, and Selly is a first-year doctoral candidate in geology at the University of Missouri studying trilobites, an extinct marine animal that resembles a horseshoe crab. Selly was minding her own business in the lab when she accidentally ignited a national media frenzy. In a paper published in a leading paleontology journal on Feb. 15, 2016, Selly found that trilobites not only hunted their prey, but were more selective of their food than scientists had once believed. Selly’s discovery fills in some gaps in the history of animal predation and its role in driving the Cambrian Explosion.
Discovery News, Live Science, I Fucking Love Science and others wrote up the findings. Some headlines called the trilobites “stone-cold killers” or even “ninja attackers.”
Tara Selly discusses her research on trilobites in her office on Wed. March 2, 2016. Selly said that trilobites were selective hunters. HANNAH LAZO.
“This whole process has been so weird for me, that like everyone’s picking up my freakin’ story,” Selly said.
When it was first published, she said she thought it was cool, but didn’t think people would care as much as they did.
As one of the first people in her family to go to graduate school, Selly said she wasn’t always sure she would get to the point in her academic career where she would be pursuing a doctorate, let alone be fielding questions from national media outlets. Before any of the recognition, Selly was just doing what she liked to do: research the history of life.
Unearthing Ancient Life
Conducting paleontological research isn’t always as glamorous as it appears in movies like “Jurassic Park,” where scientists are shown out in the field, dusting off bones with toothbrushes. In her case, Selly said she spent hours in the lab cleaning, measuring and analyzing hundreds of trace fossils that show the imprint of trilobites feeding at burrows once home to unknown, worm-like animals. When they were alive 500 million years ago, trilobites lived in the shallow sea that covered southeastern Missouri.
“We were able to show that these early animals had sophisticated behaviors by using their eyes and perhaps chemosensory techniques, that they were selectively picking out their prey,” Selly said. “So it shows some type of sophistication in early evolutionary history.”
James Schiffbauer, an assistant professor of geology at MU and one of the study’s coauthors, said the study showed trilobites used a sophisticated hunting strategy at a relatively early point in the history of. He said that prior research observed a few instances where trilobites were preserved while feeding on a burrow.
What makes Selly’s research unique is she had hundreds of fossils while other well-regarded papers were published on a single fossil. Kevin Shelton, another geology professor at MU, discovered the unusually large cache of fossils during a field trip to the Davis Formation near Leadwood, Missouri. The trace fossils were plainly visible atop the outcropping.
The sheer number of fossils they found made statistical analysis possible, Schiffbauer said. They were able to ask and answer questions about selectivity, such as what sized burrow were the trilobites most likely to attack. The study found trilobites preferred smaller, narrower, worm-like organisms.
“Any contribution to understanding evolution, not just on the planet today, but evolutionary history, I think is a worthwhile endeavor,” Schiffbauer said. “It’s an important contribution to our understanding of biology on the planet.”
He said Selly’s research fills in some missing information on the behavior of early predation and helps to explain how hunting contributed to Cambrian Explosion, an evolutionary event that began 535 million years ago.
The Cambrian Explosion was a period in Earth’s history where the ancestors of modern life begin to be preserved in the fossil record. Calling it an explosion can be a bit misleading because it implies the emergence of these new life forms occurred instantaneously, while in reality it unfolded over the course of 30 million years, according to PBS.
“It actually probably was more normal evolution; we just don’t have a record of it before that, so it just appears that way,” Selly said.
Becoming a Paleontologist
Selly grew up in Mankato, Minnesota, about an hour south of the Twin Cities. Selly, an only child, said she remembers her parents asking her what she wanted to be when she grew up, and she would always respond the same way: a paleontologist.
“We sure got a kick out of it,” Tara’s father, John Selly, said. “That’s a big word for a little girl.”
Her mother, Gina Selly, said her daughter already knew all the names of different dinosaurs by age 4 or 5.
“I thought it was just a phase she would grow out of,” Gina Selly said. “It’s kinda crazy.”
When Tara Selly started attending Gustavus Adolphus College in St. Peter, Minnesota, she said she was thinking of becoming a doctor but soon realized the entry-level classes didn’t grab her attention. She ended up majoring in biology and geology.
“It was always something that I wanted to do, but I didn’t realize for like years that it was an actual job that you could have,” Selly said. “I decided to just go for it and actually enjoy what I was doing.”
Despite her early interests, Selly said her path to pursuing a master’s degree, and eventually a doctorate, wasn’t always clear.
“I knew I wanted to go to grad school, but I never even thought I was cut out for that or anything because no one in my family has ever really gone to college,” Selly said. “So I didn’t know what it really was like.”
She said she experienced similar insecurities when on the brink of finishing graduate school, going back and forth between wanting to try and not knowing if she had it in her.
“There’s this thing – in not just geology, I’m sure it’s all of academia – that’s called the imposter syndrome,” Selly said. “You keep thinking that the further you go, you got there on accident or you’ve just been kind of faking it till you make it.”
Schiffbauer said, from his perspective, he thought Selly had what it took to get a doctorate.
“I could tell that when she was doing her master’s degree that she really enjoyed the research side of it with just her diligence in collecting data,” Schiffbauer said.
Schiffbauer said he realized Selly was the real deal when the two went to an international meeting in Canada where he had encouraged her to give a talk about her research.
“It was during that 15 minutes of the talk that I thought, I have to get her to stay for a Ph.D. because I know she can do this,” Schiffbauer said. “I had confidence where she was missing confidence.”
Selly said it wasn’t until Schiffbauer and another faculty member sat her down one day to ask about her about her post-grad plans that she made the decision to continue on for another round of school.
“I wouldn’t recommend to everyone to do a Ph.D.,” Schiffbauer said. “In my observation of Tara, I thought she could contribute to this field if she kept at it.”
Going for the Doctorate
One day in early March, midway through the first year of her doctorate, Selly stared at a tray filled with rows of pinkie-fingernail-sized snail shells laid out on her desk and pointed out that many of them had pin prick-sized holes in them. The holes were created by another organism drilling into the shell, she said.
Her interest in predator-prey interactions has shaped her research pursuits, often opting to study predation. Such is the case with her work on the snail shells and her doctorate research proposal. She’s waiting to hear back on the status of a grant proposal to take a closer look at some 600 million-year-old embryos to see if she can figure out what animal they were.
Schiffbauer said the embryos were discovered at the Doushantuo Formation in South China. Previous research by Shuhai Xiao found they are not only animal embryos, but the oldest known animals on Earth. Xiao was Schiffbauer’s advisor during his years in school and helped Selly get access to the fossils.
A rock containing the oldest known embryos on Earth sits adjacent to the journal where the initial research was published. The cover shows a very close up image of the embryos. Click here to open an interactive image. HANNAH LAZO.
“We don’t know any other animals from that timeframe, but what we do know from looking at these guys is the developmental stages represented here are exactly like the embryonic stages of modern animals,” Schiffbauer said.
Looking Ahead
Looking towards the future, Selly said she hasn’t decided which path she wants to take with her doctorate. Many people in her field go the route of academia, but she said another option would be to work for a museum, where she could do research on its collections.
“I would also like to participate more in outreach and getting the general public more interested in not just paleontology, but having a better understanding of geology, like how the world around them works,” Selly said.
She said that the media frenzy around her research has been a weird experience, one that has made her think more about the importance of being able communicate her work accurately to the public.
“Sometimes things can get embellished and then it ends up looking bad on the scientist,” Selly said. “I’ve seen that happen several times.”
Fortunately, she had a good experience with articles about her work.
Selly might have moved on from the backyard sandbox of her youth, but she’s never stopped trying to uncover more about the history of life.
Unearthed 