Researchers in the College of Science and Technology are refining a method to geolocate fossils, which play a key role in understanding how Earth has reacted to past climate changes. The research may also help places like Badlands National Park curb fossil poaching.

Dennis Terry and Mattison Shreero both remember being captivated the first time they laid eyes on Badlands National Park in South Dakota. The park’s towering rock spires and rolling hills of sediment sparked a fascination that has driven them to study and protect one of the world’s richest fossil deposits.  

“Every time a fossil is stolen, a piece of our scientific heritage is lost,” said Terry, associate professor of earth and environmental science in the College of Science and Technology. “The fossils at Badlands are so important for understanding this point in geological time where global climates change from warm and wet, to cool and dry.”

The pair received funding from the U.S. Department of the Interior (National Park Service) to improve a method of chemically tracing fossils back to the rock layers where they were preserved, helping scientists better understand the planet’s past while protecting its priceless fossil resources.

They will present some of their findings next month in Cleveland at the annual Society of Vertebrate Paleontology meeting.

Terry has spent more than three decades using Badlands National Park as a natural laboratory to study landscapes, climates and environments during the Paleogene, the time period ranging from 66 to 23 million years ago. Fossils, and the strata they come from, play an important role in his research, as they contain clues about the planet’s climate throughout time.

Shreero came to Temple in 2025 to enroll in CST’s geoscience PhD program, where she is supporting Terry’s work in Badlands National Park.

The researchers use a process called geochemical fingerprinting to determine where a fossil originated after it’s been removed from the ground. It is a process that paleontologists have long sought to master, because fossils lose most of their scientific value if the precise rock layer and location they came from is not known.

“We can’t tell the age of a fossil without knowing the age of the rock layer it came from,” said Shreero, who worked as a park ranger at Badlands before coming to Temple. “Signatures in the rock also tell us about the environment that the critter lived in.”

Rare earth element signatures have historically been used in geochemical fingerprinting, but Terry and Shreero are pioneering a method that also utilizes carbon and oxygen isotope signatures.  

Each fossil contains a combination of rare earth elements and isotopes, a “geochemical fingerprint,” that reflects the environmental conditions at the time of fossilization. Fossils from the same geographic area and layer of rock should therefore have similar signals.  

If scientists determine the fingerprint of a poached fossil, they can then compare it to signatures from fossils that were collected with geographic and geologic data and attempt to find a match to learn where the poached fossil came from. 

Using rare earth element signatures alone, Terry could find a match between 85-90% of the time. But by adding Shreero’s method of comparing carbon and oxygen isotope signatures, the pair are approaching 100% accuracy. They are using the funding from the Department of the Interior to improve their methodology with fossils from Badlands National Park.

“If we can refine our methodology and show how it can be used in Badlands National Park, then we will have a tool that any National Park Service area with fossil resources can use in fossil poaching investigations,” Terry said.

It is illegal to take fossils from public lands, such as national parks, yet fossil poaching remains a widespread issue. Fossil Cycad National Monument in South Dakota, a site once home to over 300 acres of fossils, was decommissioned in 1957 because visitors and poachers stole all of its fossils.

Terry and Shreero say rock and fossil shops in the areas surrounding Badlands commonly have poached fossils for sale. Catching those responsible, they added, is no easy task.

“Up until now, enforcement has relied on catching people in the act of poaching, which is a right place, right time thing,” Shreero said. “It’s almost impossible to do.”

Fossil poaching also thwarts scientific discovery. Researchers can use a fossil and the rock it came from to better understand what the Earth was like millions of years ago, such as the predator-prey ratio in an ancient environment, an animal’s diet or whether the climate was humid versus arid.

This information can also help scientists understand how the planet and its species may react to future changes to the environment.

“We’re really concerned right now about where the planet’s headed,” said Terry, who also worked as a park ranger at Badlands in the 1980s. “In order to understand the possible range of reactions this planet might have, we need to understand where we’ve come from.” 

Badlands is the perfect setting for Terry and Shreero’s research, as the park contains one of the most complete collections of terrestrial fossils on the planet.  

The duo is particularly concerned with fossil deposits from the time period between 37 and 30 million years ago, roughly halfway between when dinosaurs went extinct and humans emerged. It was a time filled with strange creatures like 3-foot-tall horses, the world’s first known dog species, a type of hornless deer that Shreero helped discover in 2024 and oreodonts, an unusual hoofed mammal which Shreero describes as “deer sheep camel pigs.”

Earth’s climate changed from hot and humid to cool and dry during this time. Badlands recorded this shift and its global effects, leaving behind clues that Terry and Shreero are uncovering.

“The deposits that are there preserve the richest accumulation of fossil mammals anywhere in the world, especially for this period of geological time,” Terry said. “If you want to understand how these critters survived, or went extinct, during this period when environments were changing on a global scale, this is the most important place in the world to do that.”