Paleontology in Action

Nearly five decades have passed since Orchard native Mike Voorhies spied the 12-million-year-old skull of a baby rhino jutting from an eroding bank in Antelope County in 1971. The discovery led to the uncovering of dozens of intact skeletons of rhinos, horses, tortoises, camels and more. Ashfall Fossil Beds State Historical Park, as this incredible site has come to be known, opened to the public six miles north of Royal in 1991. The quarter century since then has brought big changes at Ashfall.

Curious faces nose-up against the glass windows of the prep lab where Adrienne Ricker reconstructs an ancient rhinoceros tooth. Visitors of all ages ask all kinds of breathless questions. The intern’s favorite was, “Are there any real-life paleontologists here?” She remembers answering, “Well, Mr. Otto is a real-life paleontologist.” Another intern, Nicole Smith from Omaha, overheard and laughingly told her friend, “So are you!”

Ricker studied geology at the University of Nebraska-Lincoln and is pursuing a doctorate in earth and planetary sciences at the University of California-Santa Cruz. She chose to do a summer internship at Ashfall for several reasons. For starters, it’s cushier than some sites: the prep lab is air-conditioned, and the Hubbard Rhino Barn allows excavation to take place indoors while blocking Nebraska’s harsh summer sun. But more importantly, there’s nothing else like it in the world.

“If you want to see the pyramids, you have to go to Egypt. Ashfall is right here in our backyard,” Ricker said. “People from all over the world travel here to see paleontology in action.”

Interns like Ricker play a crucial role at Ashfall in June, July and August while interacting with visitors, prepping fossils and helping with day-to-day tasks. The short season between classes flies by quickly for students who know that the next scrape of the ash could reveal an important discovery.

“At night we dream of finding stuff,” Ricker said. One of those dreams came true when an intern uncovered the skull of a three-toed horse in the summer of 2016. The entire skeleton was there, too. Despite their considerable contributions to the park, which has been designated a national natural landmark, it is easy to see why students are a little bit wowed by park superintendent Rick Otto, the “real-life paleontologist” identified by Ricker.

Sun-tanned and khaki-clad with a determined demeanor, Otto looks the part. He’s been at Ashfall since 1978, when it was called Poison Ivy Quarry. Otto has fond memories of those early years when locals picnicked on the hill above the dig while watching scientists slowly unearth saber-tooth deer, barrel-bodied rhinos and ancient camels.

Otto is a local himself. He grew up in Pierce, where his great-great-grandparents had been homesteaders. At age 10, he was an official employee at the Conoco station his dad owned. Even then Otto had a fascination with history and animals. “I was always curious about what things were like before the pioneers,” Otto said. “That curiosity led me to wonder what things were like before the native tribes were here.”

He was 7 years old when he first visited the University of Nebraska State Museum at Morrill Hall. Fossils of mammoths and other creatures that roamed what is now Nebraska before people inhabited the plains astounded the boy. Years later, before becoming superintendent of Ashfall, he took a job as a security guard at that museum.

Otto’s growing fascination with Nebraska’s ancient past drew him into the fields of geology and paleontology. As a student at UNL, Otto worked under the mentorship of Mike Voorhies, the paleontologist who discovered that first rhino skull years earlier. A little more digging revealed another rhino skeleton. Voorhies knew something big had happened in the gully.

Scientists believe Nebraska was a subtropical grassland 12 million years ago. Saber-tooth deer, three-toed horses and giant tortoises grazed that ancient prairie around a waterhole in what is now Antelope County. Unfortunately for those critters, a hot spot beneath what is now Yellowstone National Park was brewing an eruption. A fine powdering of volcanic ash soon began falling like a dry rain over the area. Breathing the abrasive ash killed some animals within weeks. Birds and turtles went first, followed by horses, camels and rhinos. A foot or more of volcanic ash buried their corpses. Sandstone formed and encapsulated the ash layer until erosion revealed it on the edge of Melvin Colson’s corn field millions of years later.

For the rest of the story see the July/August 2017 issue of Nebraska Life.

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