“What we present here is evidence of a firm time and location,” they said.
Based on the size of the footprints, researchers believe that at least some were made by children and teenagers who lived during the last ice age.
David Bustos, the park's resource program manager, spotted the first footprints in ancient wetlands in 2009. He and others found more in the park over the years.
“We knew they were old, but we had no way to date the prints before we discovered some with (seeds) on top,” he said Thursday.
Made of fine silt and clay, the footprints are fragile, so the researchers had to work quickly to gather samples, Bustos said.
“The only way we can save them is to record them — to take a lot of photos and make 3D models,” he said.
Earlier excavations in White Sands National Park have uncovered fossilized tracks left by a saber-toothed cat, dire wolf, Columbian mammoth and other ice age animals.
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