News Release

Mammoth Cave National Park Discovers Another New Species of Ancient Shark

Proposed reconstruction of the new to science species Macadens olsoni, discovered through fossil research at Mammoth Cave National Park.

Art by Benji Paysnoe

News Release Date: July 24, 2025

Contact: Molly Schroer, 270-758-2192

MAMMOTH CAVE, KY – A new species of ancient shark, named Macadens olsoni, has been discovered at Mammoth Cave National Park, adding to the park’s rich history of paleontological finds.

“This discovery is a remarkable addition to our understanding of ancient marine life and underscores the importance of preserving and studying our natural history,” said Superintendent Barclay Trimble.

Macadens olsoni is notable for its unique tooth whorl, a curved row of teeth designed for crushing small sea creatures. This ancient shark likely grew to less than a foot in length and probably feasted on mollusks and worms. The fossils of Macadens olsoni were found in the Ste. Genevieve Formation, which dates back approximately 340 to 335 million years. During that time, Mammoth Cave was submerged in a warm, shallow sea teeming with life including crinoids and corals.

The name Macadens olsoni pays tribute to both Mammoth Cave and Rickard Olson, a retired park scientist who played a crucial role in documenting shark fossils in the park as part of a recent Paleontological Resource Inventory (PRI). The research was conducted by a team of scientists from the National Park Service Paleontology Program, Mammoth Cave National Park, and the Smithsonian Paleobiology Department. In addition to Macadens olsoni, researchers studied another ancient shark, Helodus coxanus, now renamed Rotuladens, meaning "Wheel Tooth." This species shares similarities with Macadens olsoni and highlights the diversity of ancient marine life.

“This finding not only enhances our knowledge of ancient marine ecosystems but also emphasizes the critical role of paleontological research in our national parks,” Trimble added. “Every discovery connects the past with the present and offers invaluable educational opportunities for students and the public.”

For more information about this exciting discovery and other paleontological finds in Mammoth Cave National Park, please visit Sharks, Fossils, and Caves: Secrets Revealed at Mammoth Cave.