Tracks from half a dozen species of dinosaurs turned up in an area of southern Utah that is popular with recreational riders of all-terrain vehicles (ATVs).
A section the size of a football field has been closed off to protect thousands of three-toed and other tracks, according to the Bureau of Land Management (BLM).
"Some people knew the tracks were out there, but we didn't," BLM spokesperson Larry Crutchfield told the Salt Lake Tribune for a story posted online Thursday. "But most people didn't even know they were riding over dinosaur tracks."
The footprints were laid across dozens of layers of rock and include tracks of a sharp-toothed and clawed carnivore, a three-toed crocodile, and a large plant-eating species.
(Related photo: Jurassic "Crocodile" found in Oregon [March 22, 2007])
Southern Utah is known for dinosaur fossils and tracks from the Jurassic period. These animals lived about 190 million years ago in a harsh desert that got intermittent deluges.
"You rarely find herbivores in a desert," said Martin Lockley, who heads the Dinosaur Tracks Museum at the University of Colorado at Denver.
The new sandstone prints are at least a hundred million years older than the fossils being extracted in nearby Grand Staircase-Escalante National Monument, said paleontologist Andrew Milner.
BLM paleontologist Alan Titus said the latest track find is extraordinary for its accessibility and high concentration of footprints.
"A local ATV rider told me about the site, and I had planned to go see them," Titus said of the area about 5 miles (8 kilometers) southwest of Coral Pink Sand Dunes State Park in Kane County.
"But when I saw a picture of the site, I had to get out there. I had no idea there were so many."
Copyright 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
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