Apex, the largest stegosaur fossil ever found, is going up for auction

In May 2022, Jason Cooper, a commercial paleontologist, was walking with a friend on his property near the aptly named Dinosaur City in Colorado and found a piece of femur bone sticking out of some rock.

That femur led to a stegosaur fossil, among the largest and most complete ever found, which was later nicknamed “Apex.” In July, auction house Sotheby’s will sell the Apex at auction for an estimated value of $4 million to $6 million, making the skeleton the latest flashpoint in the long-running debate over private fossil trade.

Dinosaur fossils have fetched ever-higher prices at auction houses since 1997, when Sotheby’s sold “Sue” the Tyrannosaurus rex to the Field Museum in Chicago for $8.36 million. In 2020, “Stan,” another mostly complete T. rex skeleton, sold at Christie’s for $31.8 million.

Such prices have caused serious concern among academic paleontologists, said Stuart Sumida, vice president of the Society for Vertebrate Paleontology. Many of them have watched in recent decades as fossils that could unlock scientific mysteries go into the hands of wealthy private collectors rather than research institutions.

Mr. Cooper and his colleagues unearthed a stegosaurus linked to Sotheby’s in 2023. Excavations on his property yielded numerous dinosaurs from the Jurassic period, several of which Mr. Cooper donated to institutions such as the Brigham Young University Museum of Paleontology in Provo, Utah, and the Frost Museum of Science. in Miami.

Mr Cooper described Apex Stegosaurus as a unique and scientifically important specimen. Skeletons – even partial ones – of herbivores with flat backs and pointed tails are rare. The skeleton carrier contains material of about 70 percent animal bones. At 11 feet tall and over 20 feet long, Apex is twice the size of “Sophie,” the most intact stegosaur specimen known, and has unusual proportions, incredibly long legs, and square-bottomed plates.

The specimen was also found with skin prints, possibly from the door, which will be offered as part of the sale.

Mr Cooper oversaw the preparation and mounting of the stegosaur, by 3D scanning the existing bones and mirroring elements of the specimen to fill in the gaps. The team has also collected extensive contextual data that they think may be attractive to prospective customers. The information includes a detailed site overview, quarry maps and other documentation.

Mr. Cooper also invited several palaeontologists to examine the specimen.

“If you combine the size, integrity and preservation of the bones, it’s the best stegosaurus I’ve seen,” said Rod Scheetz, a curator at Brigham Young University’s Museum of Paleontology, who examined it on Mr. Cooper’s property.

Cassandra Hatton, Sotheby’s head of science and popular culture, said the auction house had worked closely with Mr Cooper to strengthen the scientific legitimacy of this privately sold dinosaur mount, with the aim of creating a model for future auctions.

“This is the first time a specimen has been auctioned that we’ve worked on together since it was dug up,” she said. “This is the most transparent sale of dinosaurs that has ever happened.”

But Jim Kirkland, Utah’s state paleontologist, refused to endorse the stegosaurus when Mr. Cooper called on him. “Looks pretty interesting,” he wrote in an email, “but I’m not going to promote anything going up for auction. I would directly associate it with museums, but not with this one.”

Although anything can happen at a public auction, Mr. Cooper and Ms. Hatton expressed the hope that the Apex will eventually end up in a scientific institution — either through outright purchase or donation from a private collector. The team gathered data and documentation not only to convince potential buyers of the specimens’ authenticity, but also to help museums smoothly integrate such a specimen into a research collection.

“Whoever buys this also has the right to come onto my property and gather contextual information,” Mr Cooper said. “A private collector might not care about the rigors of it, but for a museum it would be really cool.”

However, the potential cost of stegosaurs may be out of reach for many institutions, Dr. Sumida said. He said that the costs of studying an already mounted and reconstructed specimen can be higher than the purchase price itself. Reconstructing and mounting fossils is as much art as science—and certain choices can be used to trick the uninitiated by blurring the lines about which parts of any given bone are real.

“If the sample is as scientifically important as claimed, then they’re doing it the wrong way,” Dr. Sumida said.

Cary Woodruff, curator of vertebrate paleontology at the Frost Museum of Science in Miami, agreed that public auctions are often “scientific slaughterhouses.” But Dr Woodruff – who also examined the specimen before the auction was agreed – suggested that compiling detailed records, images and digital scans of commercially sold fossils was something other sellers should emulate. That way, “at least traces of scientific data can exist if the specimen doesn’t end up in the public trust,” he said.

Ultimately, however, Dr. Woodruff agreed that the public trust is where such fossils belong.

“If a wealthy person were interested in collaborating with a scientific institution to contribute to scientific knowledge and progress,” he said, “then I hope such specimens would attract their attention.”