Live Science has an interesting vertebrate paleontology story.
About 315 million years ago â€” long before dinosaurs roamed the Earth â€” an early reptile scuttled along in a strangely sideways jaunt, leaving its tiny footprints embedded in the landscape, new research finds.
It’s anyone’s guess why this ancient, clawed critter walked sideways (although experts have several ideas), but one thing is certain: The animal’s prints represent the oldest-known vertebrate track marks ever discovered in Grand Canyon National Park, said Stephen Rowland, a professor of geology at the University of Nevada, Las Vegas, who is studying the fossilized trackway.
The trackway is so old, that it was made a mere 5 million years after the first known reptiles emerged on Earth, just as the ancient supercontinent Pangaea was forming. “This is right in that little window of the very first reptiles,” Rowland told Live Science. “We don’t know much about that real early history.” [Photos: Dinosaur Tracks Reveal Australia’s ‘Jurassic Park’]
The research, which has yet to be published in a peer-reviewed journal, was presented at the annual Society of Vertebrate Paleontology meeting in Albuquerque, New Mexico, on Oct. 17.
The trackway â€” preserved on a slab of sandstone measuring about 3.2 feet long and 18 inches wide (1 meter by 45 centimeters) â€” contains 28 prints from the mystery animal’s front and back feet. A friend of Rowland’s first noticed the fossilized tracks in 2016 while hiking along the Grand Canyon’s Bright Angel Trail, located on the Manakacha formation in northern Arizona.
When Rowland visited the site in May 2017, the 2-inch-long (5 cm) prints befuddled him. At first glance, the track marks looked as if they were left by two animals walking side by side, “which is very bizarre for an early reptile,” he said. After lying awake at night, turning the images over in his mind, Rowland had an epiphany: The animal that left the tracks was moving sideways.