T. Rex Skull Brings $6.1 Million at Sotheby’s, Well Below Estimate

This year, one tail vertebra from a long-necked dinosaur was auctioned off for more than $8,000. A single spike from a Stegosaurus’s tail sold for more than $20,000. A Tyrannosaurus rex tooth? More than $100,000.

In a booming market for dinosaur fossils, Sotheby’s estimated that a T. rex skull it was auctioning would fetch between $15 million and $20 million. But at its sale on Friday, the specimen was sold for $6.1 million, including fees, to an anonymous buyer.

The auction raised questions about whether the gold rush moment for dinosaurs — which has upset many academic paleontologists who fear that their research is being turned into trophies — was showing signs of ebbing.

The sale in New York comes after the planned auction of a larger T. rex specimen, estimated to sell for between $15 million and $25 million, was scrapped by Christie’s in Hong Kong after questions were raised about how much real dinosaur bone was included.

Todd Levin, a veteran art adviser, said the collapse of the Christie’s sale might have injected some uncertainty into the market for fossils.

“It’s all based on confidence,” Levin said after the sale on Friday, “and right now, there’s very low confidence in that arena.”

Earlier this year, dinosaur fossils had been a boon to the auction houses: Christie’s sold a Deinonychus skeleton for $12.4 million, and a Gorgosaurus skeleton went for $6.1 million at Sotheby’s.

The questions about the Christie’s T. rex specimen, nicknamed Shen and put up for auction by an anonymous consignor, revolved around how much of the skeleton was replica bone from another dinosaur — a common practice when mounting skeletons.

The replica bones used in Shen were casts from a famous specimen, named Stan, which broke a record for fossil sales when it fetched $31.8 million at a Christie’s auction two years ago, supercharging the industry.

Sotheby’s said the skull that sold at Friday’s auction, nicknamed Maximus, was supplemented by resin casts of another T. rex owned by the anonymous seller, who also prepared the specimen for auction. Buyers were told by the auction house that the skull “contains 30 bones of the approximate total of 39 bones,” and they were given a diagram of a skull with the real bone colored in. (From the diagram, a potential buyer could tell, for example, that not all of the T. rex’s teeth were real.)

The skull, which weighs more than 200 pounds, was discovered on private land in an area of northwestern South Dakota known for being rich with fossils, the auction house said.

For years, the high prices for fossils have rankled academic paleontologists who are afraid that scientifically important specimens will disappear into the showrooms of the wealthy. As auction prices have risen, experts at museums and universities have become increasingly concerned that institutions like theirs will be boxed out of the market.

Some specimens that have been put on the auction block did not strike scientists as impressive enough to worry about losing, but James G. Napoli, a paleontologist and researcher at the North Carolina Museum of Natural Sciences, said Maximus appeared to be scientifically important.

“This is something that I would want to study in my research if I could,” said Dr. Napoli, who studies variation between dinosaur specimens. “We always hope that it will be bought by an institution or an individual who will donate to one.”

Auction houses tend to say that they, too, hope that the specimens they sell end up in a museum for the public to view and scientists to research — but who places the winning bid is not in their control.

After more than a year of mystery about where Stan the T. rex would end up, National Geographic reported that the specimen would be housed in a developing natural history museum in Abu Dhabi, the capital of the United Arab Emirates.

“We can’t get around the fact that we live in a capitalist society; this is how our world works,” said Cassandra Hatton, the global head of science and popular culture at Sotheby’s, who organized the auction. “Perhaps they will end up in private hands for a time, but I think they will eventually end up in museums.”

In a statement after Friday’s auction, Hatton said it can be difficult to assess the value of a specimen when there have been few historical parallels.

“Today’s sale was always designed to gauge the market,” Hatton said, noting that there had been no minimum price at which the consignor had agreed to sell, “and we are pleased to have set a significant new benchmark for dinosaur fossils at auction.”

Sotheby’s had a major role in the introduction of dinosaur bones as the centerpiece of auctions. In 1997, after a legal battle over the ownership of a T. rex skeleton named Sue, the auction house sold it to the Field Museum of Natural History in Chicago for $8.4 million (or $15.4 million when adjusted for inflation).

Henry Galiano, a fossil appraiser who was a consultant for Sotheby’s on both Sue and Maximus, described the recently sold skull as an important research specimen, pointing out evidence of scarring and lesions from a possible infection. Tiny holes on the surface indicate that insects may have attacked the carcass before it was buried, he said.

The specimen had been mostly eroded when it was discovered, but in addition to the skull, the buyer will also receive a partial scapula and other fragmentary bones that are believed to be from the same individual.