In Jurassic times, dinosaurs of every stripe gathered at an oasis surrounded by high sand dunes to drink and perhaps, show off their moves. Geologists from the University of Utah say they’ve identified thousands of dinosaur footprints in an area of the Vermilion Cliffs National Monument on the Arizona-Utah border. What was once thought to be a field of strange potholes is now being dubbed a “dinosaur dance floor.”
In a new study [subscription required] published in the paleontology journal Palaios, the researchers argue that the tracks were formed by large animals, not by erosion as previously thought (and some still think). About 190 million years ago, before the continents broke from Pangaea, the site was probably a watering hole in the middle of long stretches of desert that attracted large groups of thirsty dinosaurs. Later, shifting sand dunes covered the area and preserved the prints in sandstone.
The researchers identified four different footprint shapes, ranging from 1 to 20 inches, as well as tail drags. Stepping into wet sand often creates ridges of sand around an imprint, and that’s exactly what the scientists found around one-third of the footprints. The orientation of the prints suggests the dinosaurs were traveling in a west-southwest direction.
The variety and density of prints is unusual: The researchers report finding an average of 12 footprints per square meter. The senior scientist on the project, Marjorie Chan, says (we assume from experience) that stepping in the footprints of the dinosaurs feels just like playing “Dance Dance Revolution.”
Image: flickr/ adrigu