Apex: Largest stegosaurus skeleton ever found to fetch millions at auction

Sale of the 150-million-year-old fossil could draw criticism from scientists who want them to be preserved in museums.

The largest and most complete stegosaurus ever found is up for auction in New York next week and is expected to fetch up to $6m.

Named Apex, the 150-million-year-old skeleton – 11 feet (3.3 metres) tall and nearly 27 feet (8.2 metres) long – was put on display at Sotheby’s on Wednesday and will be exhibited until its sale on July 17.

Cassandra Hatton, Sotheby’s global head of science and popular culture, underlined the rarity of the find. “This is between 79 and 85 percent fossil,” she said.

“If you find half of a dinosaur, that’s considered a significant scientific discovery. Sixty percent is incredible, and once you’re getting to 70, 80 percent, the whole world pays attention.”

Bidding is likely to be brisk, with the auction house estimating Apex’s value at $4-6m. Such sales of coveted dinosaur fossils have drawn criticism from the scientific community, which says finds should be preserved in museums or other public spaces and not sold to private bidders.

The name Apex was given to highlight its prominence within the stegosaurus family. Dinosaurs are “awesome”, said Hatton. “Who wouldn’t be excited about these massive creatures? I think we’ve been talking about them forever. We’ve kind of built them into mythology, the concept of dragons and Godzilla.”

Apex was discovered in May 2022 on the private land of palaeontologist Jason Cooper in Colorado’s Morrison Formation in the United States. Sotheby’s closely collaborated with Cooper to document the entire process of discovery, excavation, restoration, preparation, and mounting.

“That’s how we’re able to guarantee the authenticity of the animal, actually seeing it come out of the ground, understanding how it was prepared, all of the processes undertaken to get it here,” said Hatton.

In 2022, Christie’s auction house had to withdraw a tyrannosaurus rex skeleton a few days before a scheduled auction in Hong Kong due to doubts about its authenticity.

Apex was of an “advanced adult age” and probably lived a peaceful life, said Hatton.

“The sacral bones are fused, which tells us that it had arthritis. There are no bite marks or any other signs of a battle, so it’s likely that it just died of old age.”

Experts were able to ascertain that the animal died with its tail curled underneath its body. “So, it was in a death pose like a dog or a coyote or any other animal that knows it’s dying will kind of curl up on itself, and that’s what this animal did too,” said Hatton.

Stegosaurus skeletons are already on display around the world. According to Sotheby’s, Apex is 30 percent larger than Sophie, the most complete stegosaurus on public display to date, which is housed in the Natural History Museum in London.

Stan, the world’s most complete tyrannosaurus rex skeleton, sold in 2020 for a record $31.8m.