The skeleton of a T. rex is going to be auctioned in New York this month.
The Gorgosaurus skeleton will be featured at the auction.
The western United States and Canada were once home to the Gorgosaurus, an apex predator. The rex was 10 million years older than it is today.
The specimen being sold was found in the Judith River Formation. It is almost 10 feet tall and almost 6 feet long.
The only specimen available for private ownership is the Gorgosaurus skeleton, which is in a museum collection.
"In my career, I have had the privilege of handling and selling many exceptional and unique objects, but few have the capacity to inspire wonder and capture imaginations quite like this unbelievable Gorgosaurus skeleton," she said.
The fossil is expected to sell for between $5 million and $8 million.