Nearly 300 Tyrannosaurus rex bones that were dug up from three sites in the United States and assembled into a single skeleton sold Tuesday at an auction in Switzerland for 4.8 million francs ($5.3 million), below the expected price.

The 293 T. rex bones were assembled into a growling posture that measures 38 feet long and 12.8 feet high. Tuesday’s sale was the first time such a T. rex skeleton went up for auction in Europe, said the auction house, Koller.

The composite skeleton was a showpiece of an auction that featured some 70 lots, and the skull was set up next to the auctioneer’s podium throughout. The skeleton was expected to fetch 5 million to 8 million Swiss francs ($5.6-$8.9 million).

“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 dino. I hope it’s going to be shown somewhere in public.”

Green did not identify the buyer, but said it was a “European private collector.” Including the “buyer’s premium” and fees, the sale came to 5.5 million Swiss francs (about $6.1 million), Koller said.

Promoters say 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.

Often lose their heads

Koller said “original bone material” comprises more than half of the restored fossil. The auction house said the skull was particularly rare and also remarkably well-preserved.

“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.”

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.

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.

Two years ago, a triceratops skeleton that the Guinness World Records declared as the world’s biggest, known as “Big John,” was sold for 6.6 million euros ($7.2 million) to a private collector at a Paris auction.