Fossils of chipmunk shark, an ancient species with an adorable name, found in Mammoth Cave

Researchers at Mammoth Cave National Park have uncovered a small, but significant addition to their ongoing Paleontological Resource Inventory (PRI) with the discovery of a previously unknown Chipmunk Shark species.

Clavusodens mcginnisi, or McGinnis’ nail tooth, lived roughly 340 million years ago, when Kentucky was still covered in a warm, shallow sea during the Mississippian Period. The small shark measured between three and four inches in length.

According to a release from Mammoth Cave National Park, the creature’s small size allowed it to avoid larger predators and feed on small crustaceans, worms, and brachiopods found on the sea floor.

The discovery was made in the Ste. Genevieve Formation rock layer, a popular section of tours at the park.

Cave specialist Rick Toomey says that while the fossils themselves were discovered years ago, the park just recently acquired the resources and experts necessary to identify them.

“It’s part of our ongoing work on the sharks that J.P. Hodnett’s been doing as part of our Paleontological Resource Inventory,” Toomey said.

Hodnett has assisted cave researchers in the identification of several new-to-science ancient shark species in recent years, including Strigilodus tollesonae, Troglocladodus trimblei, and Glikmanius careforum.

“This is everything from our brachiopods and crinoids and sharks from the limestones we have here, to plant fossils that we have from our sandstones, to the short faced bear and saber toothed cat and bat fossils that we have from in the caves after they formed,” Toomey explained.

The shark’s namesake, David McGinnis, began his park service career as a guide at Mammoth Cave National Park. Later, he became the chief naturalist at Badlands National Park where he gained renown for his work as an advocate for fossil preservation.

He later became superintendent of Fossil Butte National Monument in Wyoming.

“Throughout his career, he pushed for recognition that fossils were an important resource that the park service was protecting, so we’re very happy to be honoring him with this new shark,” Toomey said.

In-depth analysis of McGinnis’ nail tooth and the rest of the recent additions to the five-year PRI will be released in the coming months.