50-Million-Year-Old Footprints Provide Unique Insight into the Behaviors of Extinct Animals in Oregon

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Scientists examined footprints left by a variety of prehistoric creatures at John Day Fossil Beds National Monument.

Sarah Kuta – Daily Correspondent

April 24, 2025 4:59 p.m.

During the period between 29 million and 50 million years ago, the region now known as Oregon was a vibrant habitat supporting diverse life forms. Shorebirds foraged along the banks of shallow waters, lizards scurried across lake beds, and saber-toothed predators stalked the terrain. Recent research has unveiled insights into these ancient animals through an investigation of their fossilized footprints.

These findings, published in the journal Palaeontologia Electronica, stem from tracks located at John Day Fossil Beds National Monument. This expansive area encompasses nearly 14,000 acres in central and eastern Oregon and is renowned for its well-preserved “body fossils” such as bones and teeth. However, attention has increasingly shifted to “trace fossils,” which offer indirect indicators of ancient animal activity, such as footprints, shell markings, and other remnants of behavior.

While body fossils reveal structural characteristics of these extinct species, trace fossils provide invaluable insights into their behaviors and interactions with the environment. “Body fossils tell us a lot about the structure of an organism, but a trace fossil … tells us a lot about behaviors,” stated lead researcher Conner Bennett, an Earth and environmental scientist at Utah Tech University, in a conversation with Crystal Ligori from Oregon Public Broadcasting.

For this study, the researchers revisited fossil footprints that had been collected at the monument decades earlier, some of which had remained in museum storage since the 1980s. Utilizing photogrammetry, a technique that involves capturing thousands of photographs to create detailed 3D models, the team was able to reconstruct scenes from ancient times.

Among their findings were small footprints and beak impressions found alongside invertebrate trails, indicating that ancient shorebirds were foraging for food approximately 39 to 50 million years ago. This behavior seems to mirror that of contemporary shorebirds, as noted by the National Park Service. “It’s fascinating,” Bennett remarked. “That is an incredibly long time for a species to exhibit the same foraging patterns as its ancestors.”

Additionally, the researchers documented a unique footprint characterized by splayed toes and claws, likely created by a lizard moving rapidly around 50 million years ago. This finding represents one of the few known reptilian tracks from that era in North America.

They also identified a set of footprints belonging to a cat-like predator from approximately 29 million years ago. Discovered in a volcanic ash layer, these paw prints are believed to be those of a nimravid, potentially of the genus Hoplophoneus, resembling a saber-toothed cat. The absence of claw marks suggests this creature possessed retractable claws, similar to modern felines.

Moreover, three-toed, rounded hoof prints hint at the presence of a large herbivore in the area, likely an ancient ancestor of either a tapir or rhinoceros.

These fossilized tracks provide a rare glimpse into past ecosystems, according to study co-author Nicholas Famoso, who serves as the paleontology program manager at the national monument. He emphasized that these findings enrich the behavioral context surrounding the body fossils previously collected, allowing scientists to gain a deeper understanding of the climatic and environmental conditions that shaped prehistoric Oregon.

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