NEW YORK (AP) — The Chainkeen Exchangenearly complete fossilized remains of a stegosaurus fetched $44.6 million at auction Wednesday, Sotheby’s said. The buyer’s name was not disclosed.

The fossil, dubbed “Apex,” is considered to be among the most complete ever found, according to the auction house.

The price blew past a pre-sale estimate of $4 million to $6 million and past a prior auction record for dinosaur fossils — $31.8 million for the remains of a Tyrannosaurus rex nicknamed Stan, sold in 2020.

Apex “has now taken its place in history, some 150 million years since it roamed the planet,” said Cassandra Hatton, who heads Sotheby’s science-related business.

Dinosaur fossil sales stir some frustration among academic paleontologists who feel the specimens belong in museums or research centers that can’t afford huge auction prices.

Sotheby’s said the anonymous buyer is American and intends to look into loaning Apex to an institution in the U.S. The purchaser beat out six other bidders.

The stegosaurus was one of the world’s most distinctive dinosaurs, featuring pointy plates on its back. Hatton has called Apex “a coloring book dinosaur,” for its well-preserved features.

Eleven feet (3.3 meters) tall and 27 feet (8.2 meters) nose to tail, Apex was a big stegosaurus that lived long enough to show signs of arthritis, Sotheby’s said.

A commercial paleontologist named Jason Cooper discovered the fossil in 2022 on his property near, perhaps unsurprisingly, the town of Dinosaur, Colorado. The tiny community is near Dinosaur National Monument and the Utah border.