Most expensive dinosaur skeleton ever now on display in New York City

The most expensive dinosaur fossil ever sold at auction is now on public display at the American Museum of Natural History (AMNH) in New York City.

"Apex," is a Stegosaurus skeleton unearthed in May 2022 near Dinosaur, Colorado by commercial paleontologist Jason Cooper. The dinosaur was found in the Morrison Formation, a layer of sedimentary rock laid down in the late Jurassic period. Like other fossil animals in this formation, Apex lived approximately 150 million years ago.

The fossil is also notable for being remarkably complete. About 80% of the skeleton's bones are accounted for, making it one of the most complete Stegosaurus fossils ever discovered. That completeness, in combination with other Stegosaurus fossils, will help paleontologists learn more about how Stegosaurus grew from kitten-size hatchlings to animals longer than a minibus.

"As exciting as it is to have this dinosaur on display, it is even more exciting to have the opportunity to study it and make important scientific data available for research," Roger Benson, the museum's Macaulay Curator of Paleontology, said in a statement. "Stegosaurus is one of the top dinosaurs known by the general public, but scientifically, we have much more to learn."

Apex is 11.5 feet (3.5 meters) tall and 27 feet (8.2 m) long. It is mounted with its spiked tail raised high, as if the dinosaur were about to defend itself. The specimen does not belong to AMNH, but is being loaned by its buyer, hedge fund manager and billionaire Kenneth C. Griffin. Griffin bought the skeleton at auction for $44.6 million in July 2024.

That purchase price made Apex more expensive than the previous record-holder, a T. rex named "Stan" that went for $31.8 million in 2020. Illustrating the hazards of the private sale of specimens, Stan disappeared from the public eye for two years after the sale, alarming scientists who worried the fossil's scientific value would be lost.

Stan turned up in Abu Dhabi in 2022, however, and is slated to go on display in 2025 in a newly built National History Museum there. Apex will also be available to the research community for the immediate future, according to the statement. AMNH plans to display the skeleton for four years. After that, a cast will replace the original bones. Meanwhile, Griffin has endowed a three-year postdoctoral fellowship for the study of Apex. According to the museum, the goals are to identify which species of Stegosaurus Apex is as well as investigating the metabolism and growth of stegosauruses. Scientists will take a sample of the dinosaur's thigh bone and also conduct CT scanning of the structure of its skull.

While Apex is the priciest dinosaur ever auctioned, a recent sale set another record: longest dinosaur ever auctioned. Last month, a 70-foot (21 meter) Apatosaurus skeleton sold for more than $6 million in France. The anonymous winner of the auction said scientists would have access to the skeleton for study.