Fossil Footprints In Oregon Show Ancient Shorebirds, Cats And Lizards Behaved Like They Do Today

Newly discovered fossils show that shore birds, lizards and cats were foraging and hunting in Oregon 50 million years ago in much the same way they do today.

A team of scientists led by fossil track specialist Conner Bennett identified and analyzed four sets of vertebrate trace fossils discovered at John Day Fossil Beds National Monument, and published their findings in Palaeontologia Electronica.

The fossils show the first known fossil tracks of birds and lizards at the monument, which encompasses nearly 14,000 acres and is home to one of the longest and most complete fossil records of plants and animals from the Age of Mammals and Flowering Plants.

“This prehistoric behavior from 50 million years ago is still prevalent today in modern shorebirds,” Bennett said in a statement. “Its fascinating. That is an incredibly long time for a species to exhibit the same foraging patterns as its ancestors.”

The fossilized tracks were recovered from two rock layers. Dated to between 50 million and 39 million years ago, two small bird tracks were found alongside invertebrate trails and beak marks, suggesting ancient shorebirds foraged for food in shallow water just like modern birds.

Dated to around 50 million years ago, a rare fossil track displaying clawed, splayed toes suggests a lizard ran across a lakebed. The fossil is “one of the few known reptile trackways from this time period in North America,” scientists said.

Dated to 29 million years ago, paw prints found in a volcanic ash layer may belong to a nimravid, a saber-toothed, bobcat-sized predator such as Hoplophoneus. Scientists say the lack of claw marks suggests retractable claws like modern felines.

Also dated to 29 million years ago, the final set of tracks are three-toed, rounded hoofprints believed to belong to a large herbivore such as an ancient tapir or rhinoceros.

“These tracks offer a rare window into ancient ecosystems,” said Dr. Nicholas Famoso, the monuments paleontology program manager. “They add behavioral context to the body fossils weve collected over the years and help us better understand the climate and environmental conditions of prehistoric Oregon.” 

Unlike fossilized bones, trace fossils such as tracks show evidence of the activities of ancient and extinct animals. Some of the fossils had been in museum storage since the 1980s, and researchers used photogrammetry to combine “thousands” of photos to create 3D models of the tracks.

“The fossil tracks not only help us confirm the existence of these animals in this time and place, but they also tell us how they lived,” said Bennett. 

The monument’s Thomas Condon Paleontology and Visitor Center houses thousands of fossil specimens, and its research laboratory is open to the public.