US researchers have discovered a "dinosaur graveyard" in southeastern Utah that is yielding a wealth of fossilized animals and footprints from the Jurassic and Cretaceous periods, a newspaper report said on Friday.

The centerpiece of the new finds is the well-preserved skeleton of a 150-million-year-old sauropod, a long-necked herbivore, according to the Los Angeles Times.

The researchers have so far excavated only part of the fossilized skeleton, which they estimate to be about 50 feet long. "It's big and takes a lot of time," said paleontologist Luis Chiappe, director of the Dinosaur Institute and the Natural History Museum of Los Angeles County.

The skeleton was found in the remains of what was once a big riverbed and is now a light-colored stratum on the face of an exposed cliff. Nearby in the bed were the disarticulated remains of other sauropods and meat-eating dinosaurs, including the five-foot-long femur of a brachiosaur, according to the paper.

On the ridgeline of the cliff, the team found a large number of footprints preserved in sandstone, with one set of prints from the Jurassic era, which ended about 145 million years ago, the paper said.

Prints of a sauropod were also found near tracks of carnivorous theropods and herbivorous ornithopods from the early Cretaceous period, which ended about 65 million years ago, said the paper.

Chiappe said most stunning of all, were the three-toed prints of a European stegosaur, named Deltapodus. "Deltapodus tracks have never been found in North America," he said.

Chiappe and his staff expect to spend at least another decade excavating the site, the paper said.

(Xinhua News Agency October 18, 2008)