With an estimate of $5m-8m, the sale is part of its live Natural History auction in New York on July 28.
The remarkably pristine skeleton of this Gorgosaurus was discovered in the Judith River Formation, Montana in 2018 and measures nearly 10ft (3m) tall and 22ft (6.7m) long.
Due to the conditions of the sediments in the area in which it was found, the specimen has a particularly well preserved skull, including a left maxilla and cranial bones. In addition to its condition, its location south of the Canadian border makes it one of only a tiny handful to be discovered in the United States.
All known skeletons, both from the US and Canada, are housed in institutional collections, making this the only specimen of its kind available for private ownership.
The Gorgosaurus was a member of the Tyrannosaurid family native to Western North America and was a smaller, close relative of the Tyrannosaurus rex with which it shares many features such as dozens of serrated teeth and a large head. However, palaeontologists speculate that the Gorgosaurus was faster and fiercer than the Tyrannosaurus rex, with a bite force of 42,000 newtons, rivalling the T. rex’s 35,000 newtons.
Sotheby’s, which has a historic association with dinosaur specimens as the first auction house to offer a full dinosaur skeleton in 1997, will be putting the Gorgosaurus up for auction as a highlight of its Geek Week sales series.
The specimen will be available for the public to view on display from July 21 at Sotheby’s York Avenue galleries.