Prospectors and poachers are scouring the arid badlands of the western United States in a race with scientists to find an increasingly precious natural resource: dinosaur fossils.
Public fascination with these Mesozoic beasts has triggered a competition among scientific institutions for prize specimens and created a private market in dinosaur remains, especially in Europe and Japan.
Researchers worry that some of the remains being scavenged by entrepreneurs may forever be lost to science.
"Someone who plasters [a dinosaur fossil] onto the wall of his or her chateau, that's the death knell of that material," says David Weishampel, a paleontologist who lives in Towson and teaches anatomy at the Johns Hopkins School of Medicine. "What we've got is so rare that we really can't afford that kind of activity."
Not at these prices.
Reassembled museum-quality skeletons can fetch anywhere from about $100,000 to $5 million -- with rumors of even larger offers floating among paleontologists.
And fierce disputes over ownership have erupted: Last week, a posse of federal agents raided a South Dakota fossil firm and seized a dinosaur skeleton that members of a Sioux tribe claim was illegally taken from their reservation.
"Every time there is sale of these items, it drives up the demand and spurs the market," warns David Gillette, Utah's state paleontologist, who is advising the Bureau of Land Management on efforts to catch fossil poachers.
A German archaeopteryx, a 145-million-year-old dinosaur that may be the oldest ancestral bird, was offered to Japanese collectors for $5 million, says Don Lessem, author of "Kings of Creation," a book about paleontologists.
A prize stegosaurus, he said, could fetch a similar price.
Meanwhile, Mr. Lessem says, the 30 scientists engaged in dinosaur hunting worldwide have annual research budgets that total a paltry $1 million.
"Scientists can't compete with both the legitimate and black market dealers," Dr. Gillette says.
"Landowners say, 'Other people are paying the price -- you pay the price.' "
That's what happened to Dr. Weishampel, who spent four summers studying and collecting dinosaur bones and eggs in rocky outcrops scattered around Montana's Blackfeet Indian reservation.
In 1990, Canada Fossils Ltd., of Calgary, Alberta, reached an agreement with the Blackfeet to pay royalties and hire tribe members to recover fossils from sites previously worked by another paleontologist, Jack Horner of the Museum of the Rockies in Bozeman, Mont.
The firm is hoping to supply duckbill dinosaurs to a museum in the Netherlands -- fossils that could be worth $100,000 each.
Canada Fossils' owners agreed, among other things, to let Dr. Horner monitor its work and keep some important specimens.
And they pledged not to touch Dr. Weishampel's sites.
But when tribe members who own the land where Dr. Weishampel worked found their bones might have market value, they told him he could no longer dig on their property.
While scientists usually don't have the money to pay landowners, commercial collectors will typically pay $1,000 for digging rights and up to $10,000 for each specimen found.
Dr. Weishampel says he has been forced to temporarily abandon his long-range study of major environmental changes that preceded the extinction of the dinosaurs, which occurred about 65 million years ago.
"I can examine that specific picture only in a few places, and they happen to be mostly on the Blackfeet Indian reservation," he says.
Dr. Gillette says a U.S. black market in dinosaurs has sprung up supplied by teams of poachers who trespass on federal property, raid private land without permission or even steal bones from the excavation sites of paleontologists.
These rustlers, he says, tend to be residents of small Western towns who drive out to remote sites in their pickups, set up opaque tents and, working at night, hack away with picks at bones embedded in weathered rock.
The most valuable fossils, he says, make their way into clandestine laboratories for cleaning and assembly, and are later sold to private collectors.
Scientists say poachers and unscrupulous collectors often destroy important evidence of how or when the animal lived and died, its environment, diet and behavior.
Once a fossil is carted off, it can take decades for new bones to be exposed through weathering of the rock.
Fossil rustlers are rarely caught or prosecuted, Dr. Gillette says, because they have to be caught in the act of removing the bones. Otherwise, they simply claim that the bones came from property where they have permission to remove them.
The U.S. attorney's office in South Dakota said Thursday's seizure of a Tyrannosaurus rex skeleton, believed to be the most complete fossil dinosaur of its type ever found, was part of a criminal investigation.
The Black Hills Institute of Geological Research, a private fossil firm in Hill City, S.D., dug up the dinosaur in 1990 near a town called Faith.