A geology professor at the University of Nevada, Las Vegas, has discovered that a set of 28 footprints left behind by a reptile-like creature 310 million years ago, are the oldest ever to be found in Grand Canyon National Park.
A geology professor at the University of Nevada, Las Vegas, has discovered that a set of 28 footprints left behind by a reptile-like creature 310 million years ago, are the oldest ever to be found in Grand Canyon National Park.