The Trinity skeleton is made up of bone material from three T-Rex specimens.

They were excavated between 2008 and 2013 from the Hell Creek and Lance Creek formations in Montana and Wyoming in the United States, the auction catalogue said.

The two sites are known for the discoveries of two other significant T-Rex skeletons that have gone to auction: Sue went under the hammer in 1997 for $8.4 million, and Stan, which took the world-record hammer price of $31.8 million at Christie’s, in 2020.

Last year, Christie’s withdrew another T-Rex skeleton — also excavated from Montana — days before it went to auction in Hong Kong, after doubts were reportedly raised about parts of the skeleton.

Link said Koller was intent on being open and transparent about the origins of the bones that make up Trinity.