AMERICAN FALLS — To the untrained eye, the tracks along the western shore of the reservoir look fresh — odd in shape, but recent. The fact is they were made by an ancient North American camel some 20,000 to 50,000 years ago, and the trail of tracks contains a treasure trove of information for paleontologists like Dr. Mary Thompson of the Idaho Museum of Natural History on the Idaho State University Campus.
Thompson was beaming with excitement Friday as a dozen ISU scientists and graduate students explored the trackways discovered along the edge of American Falls Reservoir last week.
Preserved tracks found in the hardened sands included those of camels, llamas and a large dire wolf or Canis dirus. All of these animals lived during the Pliocene epoch when the large lake above American Falls provided water for creatures who enjoyed a cooler climate and a heavily forested Southeast Idaho.
“Camels originated in North America, as did llamas,” Thompson said.
Animals like camels and llamas provided a food source for predators like the dire wolf. This ancient canine was about five feet in length and weighed about 130 pounds on average — slightly smaller than today’s timber wolf.
“We found bones from both those critters,” Thompson said about the camels and llamas. So far, only the tracks of one wolf have been discovered.
Thompson said determining the origin of predator tracks is more difficult because there were so many during that time period. Ancient bears and coyotes shared territories with the North American lion and two different types of saber-toothed tigers.
The llama tracks discovered by ISU’s team are Hemiauchenia macrocephala or “big-headed llamas.” The camels are Camelops hesternus or “yesterday’s camel.”
Thompson rattles off the facts about the creatures with ease because what happened in this area thousands of years ago is her passion.
“This is one of the top locations in the nation for Pliocene vertebrates,” Thompson said about the area upstream from American Falls. “It’s just behind the La Brea Tar Pits.”
Her enthusiasm for last week’s discovery of the so-called “trackways” was shared by Robert Schlader, manager of the Idaho Virtual Lab at ISU’s museum. He was busy setting up sophisticated 3-D imaging equipment with graduate students, Jessie Pruett and Kate DeHart.
Schlader explained how the equipment uses lasers and a rotating mirror to create a three dimensional image of the walkway.
“It’s essentially doing the same thing as policeman’s radar gun, except instead of measuring speed it measures distance,” Schlader said.
The grad students set up white balls along both sides of the walkway to serve as targets. Once the equipment has gathered all the data, Schlader will take it back to his lab and use it to create a virtual environment as it existed 20,000 or more years ago when the ancient animals were making tracks to the water’s edge.
“Our big goal today is to try to capture and document as much as possible of this,” Thompson said.
ISU’s scientific experts are working with the Bureau of Reclamation to survey and protect paleontology resources. A federal law passed in 2009 makes it illegal for people to remove fossils and other finds from federal land and the 21-mile long reservoir above American Falls is managed by the Bureau of Reclamation.
Archeologist Jenny Huang, who has worked for the Bureau since 2005, is coordinating efforts with ISU.
“The collection of vertebrates from federal land is now illegal,” Huang said.
Although her specialty involves ancient human activities, Huang said she enjoys working with the university’s paleontologists as the explore pre-human periods of life in Idaho.
“This is really fascinating stuff,” Huang said.
As the ISU team worked its way along the edge of the reservoir, graduate student Jeff Castro alerted Thompson to the discovery of fossilized bone. It was a large ankle bone from an ancient camel.
“Don’t move anything until we’ve documented its location,” Thompson told the group.
Armed with little flags, the students and professors fanned out and continued to pinpoint tracks and bones along the walkway.
“The trackways tell us a lot more about what the animals were doing,” Thompson said. “We’ll be at this for several days.”
And those several days of field work will translate into a more accurate glimpse of life in Southeast Idaho when a lava flow blocked the Snake River at American Falls and formed a large inland lake long before modern engineers did the same thing for irrigation thousands of years later.