Promoters said the composite T. rex, dubbed “Trinity,” was built from specimens retrieved from three sites in the Hell Creek and Lance Creek formations of Montana and Wyoming between 2008 and 2013.
The Koller Auction House in Zurich said “original bone material” comprised more than half of the restored skeleton. The auction house said the skull was particularly rare and also remarkably well-preserved.
Including the “buyer's premium” and fees, the sale came to 5.5 million Swiss francs (about $6.1 million), Koller said.
“It could be that it was a composite — that could be why the purists didn't go for it,” Karl Green, the auction house’s marketing director, said by phone. “It's a fair price for the dinosaur. I hope it's going to be shown somewhere in public.”
"When dinosaurs died in the Jurassic or Cretaceous periods, they often lost their heads during deposition (of the remains into rocks.) In fact, most dinosaurs are found without their skulls," Nils Knoetschke, a scientific adviser who was quoted in the auction catalog.
“But here we have truly original Tyrannosaurus skull bones that all originate from the same specimen,” he said.
The two areas the bones for Trinity came from were also the source of other T. rex skeletons that were auctioned off, according to Koller: Chicago’s Field Museum of Natural History bought “Sue” for $8.4 million over a quarter-century ago, and “Stan” sold for nearly $32 million three years ago.
T. rex roamed the Earth between 65 and 67 million years ago. A study published two years ago in the journal Science estimated that about 2.5 billion of the dinosaurs ever lived. Hollywood movies such as the blockbuster “Jurassic Park” franchise have added to the public fascination with the carnivorous creature.