Ancient shark species unearthed in landlocked state’s national park — and it’s over 300 million years old

Jeremiah Budin
Mon, November 27, 2023 

Kentucky, a landlocked state, would probably not be the first place you would expect an ancient shark species to have been discovered. But the world is full of surprises, as scientists recently uncovered teeth from a 300 million-year-old shark species in Kentucky’s Mammoth Cave National Park.

The teeth, which once belonged to a Strigilodus tollesonae (Latin for “Tolleson’s scraper tooth”), were found during a National Park Service research project coordinated by the NPS Paleontology Program and Mammoth Cave park officials. The species was named in honor of Mammoth Cave guide Kelli Tolleson, one of the people behind the discovery.

“The teeth of Strigilodus tollesonae were discovered within the St. Genevieve Formation rock layer at Mammoth Cave National Park,” an NPS spokesperson told Newsweek. “This would place it as living approximately 340 to 320 million years ago.”

The Strigilodus tollesonae was part of a now-extinct group of cartilaginous marine fish called petalodonts, or “petal-toothed.” Its spoon- or petal-shaped teeth were likely arranged in a fan-like structure, indicating that may have subsisted on snails, bivalves, soft-bodied worms, and smaller fish.

Photo Credit: Benji Paysnoe

As far as paleontology research projects go, finding 300 million-year-old extinct shark teeth from a never-before-discovered species has to be up there in terms of the best possible results.

According to the researchers, the Strigilodus tollesonae is more closely related to the ratfish than to any modern shark species. Ratfish reside in the deep sea and cruise the seafloor for shrimp, clams, worms, seastar, and small fishes.

Although Kentucky is landlocked today, during the time of the Strigilodus tollesonae, it was covered by shallow tropical seas. During that period, the continents of North America, South America, Africa, and Europe all existed as one single continent called Pangea.

The findings were announced to the public on Oct. 11, which, fittingly, is National Fossil Day.