A record auction sale saw Ken Griffin of Citadel purchase a stegosaurus for $45 million.

At Sotheby's on Wednesday, Ken Griffin, billionaire investor and founder of Citadel, bought a late-Jurassic stegosaurus skeleton for $44.6 million, breaking the record for the most valuable fossil ever sold at auction.

A nearly complete skeleton of a 150 million-year-old stegosaurus named "Apex," measuring 11 feet tall and nearly 27 feet long from nose to tail, was only expected to sell for about $6 million.

Griffin emerged victorious in the live auction in New York on Wednesday, having battled six other bidders for 15 minutes. It is reported that he plans to loan the specimen to a U.S. institution.

Griffin declared that Apex, which originated in America, would remain in America following the sale.

The stegosaurus was excavated on private land in Moffat County, Colorado, and there were no signs of combat-related injuries or evidence of post-mortem scavenging, Sotheby's stated.

In 2018, Griffin donated $16.5 million to the Field Museum to finance the exhibit of a life-size replica of the largest dinosaur ever found, a long-necked herbivore from Argentina.

In 2021, he purchased a first-edition copy of the U.S. Constitution for $43.2 million, surpassing a group of cryptocurrency investors in the bidding process. Later, he loaned the document to the Crystal Bridges Museum of American Art in Arkansas.