Trinity, a composite Tyrannosaurus rex skeleton, is made up of bones from three different T-Rexes.
It was sold for 5.5 million Swiss francs ($6.1 million) in an auction on April 18.
Trinity is made of dinosaurs excavated between 2008 and 2013 from the Hell Creek and Lance Creek formations in Montana and Wyoming.
The skeleton was sold at the Koller auction house in Zurich after it was shipped from the US in nine ain't crates.
It is expected to be 65 to 76 years million years old.
The skeleton was bought by a private European collector of modern art and dinosaur relics.
Trinity's auctioneer Cyril Koller said it was the third T-Rex skeleton ever sold at auction, and was the first in Europe.
Thomas Holtz, the vertebrate palaeontologist said it is misleading and appropriate to combine bones from different individuals to make one and later sell it.
Two other skeletons were auctioned from the same sites.