Trove of dinosaur tracks found

Geologists say they have discovered prehistoric animal tracks so densely packed on a 3/4-acre site that they're calling it a “dinosaur dance floor.”

The site along the Arizona-Utah state line offers a rich new set of clues about the lives of dinosaurs 190million years ago.

Back then, large stretches of the West were a Sahara-like desert. More than 1,000 tracks were found in what would have been a watery oasis nestled among towering sand dunes.

The footprints could provide fodder for researchers trying to understand dinosaurs that survived in what many considered a vast, dry, uninhabitable desert, said Marjorie Chan, professor of geology at the University of Utah and one of the authors of a new study of the site.

“Maybe it really wasn't as lifeless as we think,” she said.

The discovery adds yet another site to the region's long list of dinosaur hot spots. The difference, though, is sheer numbers. Scientists estimate there are more than 1,000 tracks at the site, which is in a protected area of Vermilion Cliffs National Monument.

In some places, there are a dozen footprints in a square yard.

“It was a place that attracted a crowd, kind of like a dance floor,” Chan said.

Researchers identified four different kinds of tracks in the rock but haven't determined the specific species that left them behind.

The area also includes what researchers think are rare tail drag marks.

Winston Seiler, who studied the site for a master's thesis, said the area might have been a popular gathering spot for adults and youngsters alike. It could have been one of many where Early Jurassic dinosaurs stopped for refreshment before moving along.

Seiler imagines dinosaurs were “happy to be at this place, having wandered up and down many a sand dune, exhausted from the heat and the blowing sand, relieved and happy to come to a place where there was water.”