On a Wednesday afternoon in mid-October, visitors to the Falls of the Ohio State Park will file into the Rotunda, the round entry hall of the park's Interpretive Center, and sit down to hear a retired dentist talk about teeth. Not dentistry, exactly — the deep history of teeth, the kind that stretches back hundreds of millions of years before there was anyone around to brush them.
The program is called "History of Teeth," and it runs from noon to 1 p.m. on October 14, 2026, at the park at 201 W. Riverside Drive in Clarksville, Indiana. The presenter is Stan Dunn, a retired dentist who volunteers with the park's Naturalist at Heart program. He has given a version of this talk before — a family-oriented edition appeared on the park's calendar in 2025 — and the format has stayed much the same: real skulls and teeth from modern animals, a talk on how teeth evolved and why they come in so many shapes, and a matching game in which participants who get the answers right go home with a fossil shark tooth.
That last detail is the sort of thing that makes the Falls of the Ohio unlike almost any other park. The fossil shark teeth are not souvenirs bought in bulk; they are the genuine article, the kind of thing that erodes out of the park's 390-million-year-old limestone beds and washes up along the riverbank. Handing one to a kid who just matched a jaw to its owner is a neat piece of theater — the ancient past used as a prize for learning about the present.
The setting is part of the story, too. The Rotunda is dominated by a giant mural showing an aerial view of the Falls of the Ohio as it looked around 1600, before engineers and locks and dams remade the river. Suspended from the ceiling above are hand-blown glass sculptures by the local glass artist Brook White, and above those, cycloramic banners introducing the center's four exhibits. One of the sculptures, "An Ancient Sea," is a delicately balanced piece of nine etched-glass platters, backlit in blue and amber, that represent fossils still visible on the beds today: a snail, a trilobite, a crinoid, a brachiopod, a bryozoan, horn coral, wasp nest coral, branching coral, and pipe organ coral. It is a fitting room in which to consider the long, strange career of the tooth.
The Falls of the Ohio is, by any measure, an odd and wonderful place to talk about evolution. During the Middle Devonian Period, roughly 390 million years ago, the area lay about 30 degrees south of the equator, covered by a shallow tropical sea. The creatures that lived and died there — corals, sponges, brachiopods, early fish — left their remains in what is now the Jeffersonville Limestone, and the result is the world's largest exposed Devonian Period fossil beds. In 1966, the fossil beds were designated a National Natural Landmark, among the first natural resources recognized by the U.S. Department of the Interior. A plaque on the south wall of the Interpretive Center notes that the site "possesses exceptional value as an illustration of the nation's natural heritage."
The park's own exhibits trace that heritage in four parts: "An Ancient Sea," set in the Devonian; "A Changing Land," which moves forward to the Pleistocene and the glaciers that carved the Ohio River; "Converging Cultures," which covers the meeting of Native peoples and European settlers from the 1600s onward; and "The Falls Today." The History of Teeth program, with its $7 fee covered by a grant from the Falls of the Ohio Foundation, includes admission to that exhibit gallery — so the hour in the Rotunda is really a doorway into the rest of the center.
The Naturalist at Heart program is itself a quiet piece of the park's institutional history. It trains volunteers to answer the questions that children, grandchildren, and friends ask about geology, river ecology, and natural and cultural history, and it puts them in front of school groups, at special events, and at the Clark home site. The park's interpretive naturalist staff works alongside what the foundation describes as "a corps of trained volunteer naturalists" to tell the story of how the fossils formed and what they mean. Dunn, a dentist by training and a naturalist by second career, is a good example of the arrangement: a specialist in the anatomy of teeth, volunteering his expertise in a place where teeth — fossilized, ancient, and otherwise — are part of the landscape.
There is a pleasing symmetry to the whole thing. The fossil beds at the Falls are famous for what they preserve of animals that had barely begun to experiment with jaws and teeth. The park's own geology records some of the earliest chapters in that story. And the program's matching game, with its fossil shark tooth prize, closes the loop: a modern animal's dentition, a Devonian relic, and a kid who now knows the difference.
The event is free to attend, with no registration or capacity limit mentioned, and it meets in the Rotunda. For anyone in the Louisville metro area — the park sits just across the river from downtown Louisville — it is an easy hour, and an unusual one. There are not many places where you can hear a retired dentist explain the evolution of teeth while standing beneath a glass sculpture of a trilobite, in a building perched above the largest exposed Devonian fossil bed on Earth, and walk out with a shark tooth in your pocket.
The Falls of the Ohio State Park can be reached at 812-280-9970. The program runs from noon to 1 p.m. on October 14, 2026.