In 1997, a Tyrannosaurus rex nicknamed Sue shattered auction expectations when Sotheby's sold it to The Field Museum in Chicago for an unprecedented $8.36 million. That remains the highest price anyone has ever paid for a dinosaur fossil at a public auction.
But Sue's record could be broken Tuesday (Nov. 19) when the so-called Montana Dueling Dinosaurs — a coupled tyrannosaurid and ceratopsid that look as if they died in combat — go under the auction hammer in New York.
Bonhams, which is handling the sale, has estimated the fossilized pair could fetch a price between $7million and $9 million — and that amount is a conservative estimate, said Thomas Lindgren, who put together the natural history auction.
"They could bring much more than that," Lindgren told LiveScience at a preview of the auction last week. "This lot could set an all-time record for any fossil that's ever been sold."
Some paleontologists fear that the dinosaurs could be lost to science if they end up in private hands and not a public collection, especially since the nation's nonprofit natural history museums may not be poised to make an offer on Tuesday.
The Field Museum in Chicago, for example, faces a much different financial situation today than it did when it purchased Sue in 1997. Earlier this year, the Associated Press reported that the museum was $170 million in debt and would be cutting its 2014 research budget by 20 percent.
"I was sent some promotional materials related to this sale, including a rather fancy, glossy catalog," paleontologist Peter Makovicky, a curator at The Field Museum, said of the Dueling Dinosaurs in an email. "However, as you may have gathered from the recent media attention to the Museum's difficult financial situation, we are in no position to consider bidding for these specimens."
And besides tight budgets, natural history museums typically don't pull in big donations from philanthropists like art museums do, paleontologist Hans-Dieter Sues of the Smithsonian's National Museum of Natural History told LiveScience earlier this month.
The fossils have been billed as the most complete dinosaurs ever to be discovered in North America's Late Cretaceous rocks. But many scientists have been dismissive of the sale and say the value of the fossils cannot truly be determined until researchers scrutinize the bones in peer-reviewed studies.
"The problem is they're asking an enormous amount of money based on very tenuous claims," Sues said. Particularly contentious among those claims is how the dinosaurs died. The identity of the species of tyrannosaurid as Nanotyrannus lancensis has also been controversial, because researchers have debated whether this type of dinosaur represents a distinct species or a juvenile T. rex.
The sale at Bonhams will take place Tuesday at 1:00 p.m. ET.
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