Fallen Boulder Reveals 313 Million-Year-Old Fossil Footprints At Grand Canyon

A geologist has discovered a pair of fossil footprints that researchers say are the oldest of their kind in the Grand Canyon, dating back 313 million years.

Researchers said the fossils show two animals passing at different times along the slope of a sand dune.

Allan Krill, a visiting professor from Norway, was hiking along a trail with a group of students in 2016 when he came across a fallen boulder containing the markings, according to a National Park Service news release.

The boulder, dropped there in a cliff collapse, held tracks that intrigued Krill who then sent a set of photos to his colleague, Stephen Rowland, a paleontologist at the University of Nevada Las Vegas.

After extensive research, Rowland called the discovery "by far the oldest vertebrate tracks in Grand Canyon."

"More significantly," he added, "they are among the oldest tracks on Earth of shelled-egg-laying animals, such as reptiles, and the earliest evidence of vertebrate animals walking in sand dunes."