"Apex" is a fossilized specimen of an unknown species in the genus Stegosaurus, discovered in Colorado's Morrison Formation in 2022.

Dated to the Late Jurassic epoch, it is the largest known Stegosaurus fossil, preserving skin impressions and throat ossicles alongside a mostly complete skeleton.

[10] Apex was discovered in May 2022 by commercial paleontologist Jason Cooper in Moffat County, Colorado, on private land near the town of Dinosaur.

[7] On July 18, the buyer was revealed to be billionaire Kenneth C. Griffin, founder and CEO of the hedge fund Citadel LLC.

[18] Both Brusatte and University of Adelaide professor Diego C. García-Bellido stated that scientific institutions were unable to keep up with private buyers at auctions.

[19] The display was also criticized, with Sumida commenting that the reconstruction and mounting required artistic choices, which would lessen the scientific and educational value of the specimen.

[20] Both discoverer Jason Cooper and Sotheby's science department head Cassandra Hatton stated that they hoped for the specimen to be acquired by a scientific institution.

[19] In December 2024, it was announced that Apex was loaned to the American Museum of Natural History, who had contacted Kenneth Griffin during the summer.

It debuted in the Richard Gilder Center for Science, Education and Innovation, where it is stationed in an atrium near the entrance, and is planned to be moved in late 2025 to the fossil halls on the fourth floor.

[24] Researchers plan to analyze a 10 centimeters (3.9 in) wedge from the femur, in order to produce the first growth curve of Stegosaurus, and to create digital models using CT scans.

The matter was described by Stuart Sumida as "a new gray area", with the Society of Vertebrate Paleontology's ethics committee due to provide a recommendation in early 2025.