Cedar City » The Grand Staircase-Escalante National Monument has yielded new fossilized treasures that a scientist says could help rewrite what is known about paleontology in North America.
"What we found will make us rethink what we know about [dinosaur] biology, ecology and migration," said Alan Titus, paleontologist with the Bureau of Land Management, which oversees the 1.9-million-acre monument in southern Utah.
Titus said bones ferried out by helicopter on Wednesday represent work performed last summer on a recently discovered site that could be the most significant yet discovered on the monument.
"It's the biggest accumulation of bones we've found on the Kaiparowits Plateau," said Titus of the site, found in 2007. "We're finding [dinosaurs] we did not know existed five years ago. All the different [species] are really helping bring the picture into focus."
In the past decade, Titus said 2,600 sites have been discovered on 50,000 acres of the monument in Kane and Garfield counties. But few have been as rich as the latest site.
"Its easily in the top three sites we've found," he said. "We're finding five or six different [dinosaurs] in one hole."
The plaster jackets that were moved out this week contained skulls and other bones of dinosaurs that roamed the area during the Late Cretaceous period 75 million years ago, when a sea cut North America into Western and Eastern land masses.
Among the fossils recovered are a near-complete skeleton of a gryposauraus, described as a duck-billed dinosaur on steroids; an ankylosaur, an armored creature resembling a low tank with a club on the end of its tail; and a pterosaur that Titus described as similar to a "flying reptilian bat."
Also removed were fossils of turtles and a crocodile that thrived in the area when it was a steamy jungle and temperatures could reach 120 degrees.
The gryposauraus, identified as a new species of dinosaur two years ago, will be reconstructed and put on display at the new Utah Museum of Natural History being built at the University of Utah in Salt Lake City.
The museum collaborated with the BLM in uncovering the specimens at the new site.
Titus said the ankylosaur fossil is puzzling because it is more like those uncovered in Mongolia than specimens found further north. He said it may force paleontologists to rethink how dinosaurs migrated to the area.
"We've always thought they crossed the land bridge from Asia into the interior [of North America]," then went south, Titus said. "But there are no similar examples of [ankylosaurs] in Montana and Canada so maybe they followed the Pacific coast line south then migrated north. It's a puzzle we're slowly piecing together."
Scott Sampson, research coordinator at the Museum of Natural History and author of a new book, Dinosaur Odyssey: Fossil Threads in the Web of Life , said the monument is truly a treasure. His book includes a chapter on the significance of discoveries on the monument.
"It's one of the greatest bone yards in the United States," said Sampson, who also hosts the children's television show "Dinosaur Train" on PBS. "The monument has opened a new window on the Late Cretaceous."
He agrees with Titus that monument discoveries are prompting paleontologists to rethink old beliefs.
Ten years ago, he said, scientists thought fossils of species found in Canadian digs were different from those found in southern Utah because they lived at different times. But recent finds on the monument have shown that species in the north existed at the same time as those in the south.
He said researchers are able to more accurately date species in the south because of the condition and number of skulls found on the monument.
Sampson said that during the Late Cretaceous, the monument was part of a relatively small piece of land known as Laramidia, which was sandwiched between an inland sea and mountains.
"It's a mystery of how so many big animals could live on such a small area of land," said Sampson.
Mike Getty, collections manager of paleontology at the Museum of Natural History who led teams uncovering the bones, described the site as the richest one so far in terms of the number of species and specimens. "This diversity and wealth gets our hopes up," said Getty. "Sites like this are not common. We hope to find more."
