The largest stegosaurus skeleton ever found, nicknamed Apex, sold for a record breaking $44.6 million at auction in New York on Wednesday, Sotheby's said.

Estimated to be 150 million years old, Apex is said to be "among the most complete skeletons ever found," according to the auction house.

It measures 11 feet (3.3 meters) tall and 27 feet long and counts 254 fossil bone elements of an approximate total of 319.

The previous auction record of $31.8 million for a dinosaur skeleton was set in 2020 for a Tyrannosaurus Rex nicknamed "Stan."

Sotheby's had expected Apex to fetch between $4 million and $6 million, but the price quickly skyrocketed as telephone bidders deluged the sale, prompting gasps and clapping in the auction room.

After the record-breaking sale, the auctioneer asked her colleague Cassandra Hatton, Sotheby's global head of science, "do you need a cigarette?"

Apex was discovered in May 2022 on the private land of paleontologist Jason Cooper. The auction house says it has collaborated with Cooper to "document the entire process, from discovery and excavation to restoration, preparation and mounting," in order to guarantee the "highest standards and transparency."

In 2022, Christie's auction house had to withdraw a T-rex skeleton a few days before auction in Hong Kong, due to doubts about its authenticity.

Wednesday's auction follows an increasing trend for the sale of dinosaur remains.

Stegosaurus skeletons are already on display around the world, but 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.