The bones of a nearly complete 161-million-year-old dinosaur are on display at Sotheby’s in New York as part of their annual Geek Week sale series. 'Apex,' billed as the most complete Stegosaurus ever discovered measures 11 feet tall and approximately 27 feet long from the tip of its tail to its nose, according to Cassandra Hatton, the Global Head of Science and Popular culture at Sotheby’s. “In terms of Stegosaurus, this is an incredibly rare animal. There are only eight or nine known in the world,” Hatton told the Associated Press during a preview visit. Sotheby's collaborated closely with the owner to document the entire process, from discovery and excavation to restoration, preparation, and mounting. “It's about 79% complete,” Hatton said. “That is based on how much of it is actually fossil bone. How much of the bones were actually found?” The Stegosaurus is the best-known member of the armored dinosaurs called Thyreophorans, characterized by the distinctive shape and arrangement of dermal armor on its back, extending from the neck to the tail. Hatton called the Stegosaurus “a coloring book dinosaur.“ “It's one of the top three most recognized and most popular dinosaurs of all time,” according to Hatton. “Apex” was discovered in May 2022 in the Morrison Formation, located in Moffat County, Colorado, near the town of Dinosaur. The excavation was completed in October 2023. The Stegosaurus shows no signs of combat or predation-related injuries. However, evidence of arthritis indicates that it lived to an advanced age. “The animal was found with the tail curled up underneath the body, which is a common death pose for animals,” Hatton said. The Jurassic period dinosaur is expected to sell for between $4 and $6 million, although Hatton pointed out that "a Stegosaurus of this caliber has never sold at auction before." The gavel drops on the live auction in New York City July 17.