- Geologist Allan Krill, a visiting professor from Norway at the University of Nevada, Las Vegas, discovered some fossil footprints while hiking with students in 2016.
- Krill snapped a photo and sent it back to Stephen Rowland, a paleontologist at UNLV. Rowland and colleagues reviewed the findings and published them in the PLOS One journal.
These are by far the oldest vertebrate tracks in Grand Canyon, which is known for its abundant fossil tracks. ... 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. — Stephen Rowland
- The researchers made the discovery after a cliff collapse. The fossils were available to see in plain sight but it was only Krill who noticed them there, according to CNN.
Why it matters:
- The fossil footprints “revealed a distinctive gait that scientists did not know about in early animals,” according to CNN.
- The footprints revealed something called a “lateral-sequence walk,” which means a back leg and front leg on one side of the animal moving together before alternating.
Living species of tetrapods, dogs and cats, for example, routinely use a lateral-sequence gait when they walk slowly. The Bright Angel Trail tracks document the use of this gait very early in the history of vertebrate animals. We previously had no information about that. — Stephen Rowland