Riverbed Graveyard Uncovered
Though the Hanksville-Burpee Quarry today is high and dry, it appears to have once been at a bend in a large, long-gone river.
A bar or other river feature likely collected the corpses of dinosaurs and other animals that died upstream and were washed down during high-water events over several centuries. The result is a logjam of fossilized bones.
The site's sandstone also encases freshwater clams, petrified trees, and other preserved matter. "There is potential that there could be burrows that contain fossil mammals. We have petrified logs—a whole group of things that I think are going to tell us something very detailed about this environment," Bonnan said.
(Related: "Ancient Mammal Relative Dug Burrows in Antarctica?" [June 9, 2008].)
The late Jurassic has been studied intensively for more than a century, yet some key questions linger.
"The big open question that remains is the environment in which the Morrison fauna and flora existed," said Hans-Dieter Sues, associate director for research and collections at the Smithsonian's National Museum of Natural History in Washington, D.C.
Sues has received funding from the National Geographic Society's Committee for Research and Exploration.
Early geologists imagined the Morrison-formation region as a vast swamp, the imagined prime real estate for all those sauropods.
"But later geologists argued that the Morrison was deposited in a dry environment with just some large bodies of water," said Sues, who is not involved with the Hanksville-Burpee dig.
New Look at Familiar Dinos?
Whatever mysteries the new site may hold, it is unlikely to produce any new dinosaur species, Sues said.
"Except for some really small dinosaurs—including possible bird relatives/precursors—or a good skeleton of the giant Brachiosaurus, there is going to be little that is newsworthy regarding Morrison dinosaurs," he said.
"The big discoveries to be made lie with other groups of Morrison animals, such as flying reptiles and mammals, which are still mostly known from very fragmentary remains."
But team member Bonnan hopes the Hanksville-Burpee will eventually rival Utah's other major Jurassic fossil troves—Dinosaur National Monument and the Cleveland-Lloyd Dinosaur Quarry.
"Even if we don't find anything new in terms of species, we're looking at old bones with new eyes and new technologies," he said.
"In the old days it was more about finding the 'biggest, baddest, bestest' dinosaurs, and a museum might have just cherry-picked those best specimens.
"Now there is more interest in the fossil assemblage—what does it tell you about the environment?"
The site will close for the season on Friday. But scientists are already anxiously awaiting the resumption of excavations next summer.
"It will take years to understand the real potential, or how big this site really is," BLM's Foss said. "But there is something there worth taking a really good look at."
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