Sunday, October 19, 2008
Arizona's "dinosaur dance floor"
The University of Utah has put out more info about a new study published in the journal Palaios:
Two UofU geologists identified an amazing concentration of dinosaur footprints that they call "a dinosaur dance floor," located in a wilderness in the Coyotes Buttes area of Arizona near the Utah border where there was a sandy desert oasis 190 million years ago.
Located within the Vermilion Cliffs National Monument, the "trample surface" has more than 1,000 and perhaps thousands of dinosaur tracks, averaging a dozen per square yard in places. The tracks once were thought to be potholes formed by erosion but former graduate student Winston Seiler [right, with some of the dinosaur tracks he identified for his thesis as a University of Utah master's degree student. Credit Nicole Miller, UU] and geology professor Margie Chan found that the range of track shapes and sizes reveals at least four dinosaur species gathered at the watering hole, with the animals ranging from adults to youngsters. [right bottom, Eubrontes dinosaur footprint (?) including three toes and a heel (?) measures roughly 16 inches long, believed to have been made by upright-walking, meat-eaters smaller than Tyrannosaurus rex. Credit Winston Seiler, UU]
The site - a 6-mile roundtrip hike from the nearest road - is in Arizona in the Coyote Buttes North area of the Paria Canyon-Vermilion Cliffs Wilderness, which is part of the U.S. Bureau of Land Management's (BLM) Vermilion Cliffs National Monument. The track site - about halfway between Kanab, Utah, and Page, Ariz. - is near a popular wind-sculpted sandstone attraction known as the Wave.
The 2.4-inch-wide tail-drag marks - which are up to 24 feet long - are a special discovery because there are fewer than a dozen dinosaur tail-drag sites worldwide, Seiler says.
[Thanks to Margie Chan for forwarding the news story on this. Much of the above was taken from the release written by my buddy Lee Siegel at the UU]