A Tyrannosaurus rex skeleton will be auctioned off to a private seller next month after going on display in Singapore.
"It's a sad thing that dinosaurs are becoming collectible toys for the oligarch class and I can only hope this fad ends soon," Steve Brusatte, a paleontologist at the University of Edinburgh, told AFP.
He said the remains belonged in museums and private sales were "bad news for science".
The 1,400-kilogram skeleton will be the first T-rex skeleton auctioned in Asia, according to auction house Christie's.
The T-rex, called Shen — or god-like — will be on display for three days before being shipped to Hong Kong next month to be sold.
The adult dinosaur, which is 4.6 metres tall and 12 metres long, is made up of about 80 bones. It was excavated from private land in the US state of Montana in 2020.
Shen, thought to be male, lived during the Cretaceous period about 67 million years ago.
Christie's gave no price estimate for the lot.
A T-rex known as Stan was sold for $31.8 million by Christie's in 2020.
In July, the first skeleton of a Gorgosaurus went under the hammer for $6.1 million in New York.
"None of the 20 T-rex that exist in the world are owned by either an Asian institution or an Asian collector," said Francis Belin, president of Christie's Asia Pacific.
"We really wish that Shen will find a new home among our Asian collectors here."
But the trend for prehistoric auction lots has some experts concerned.
Thomas Carr, a paleontologist from the US, described such sales as "unquestionably harmful to science" even if the skeletons had been studied before being sold.
"A secure, permanent collection ensures that the observations that a scientist makes of a fossil can be tested and replicated — and a commercially held fossil has no such assurance," Mr Carr said.
Mr Belin said he hoped a public institution would buy Shen. He said the whole skeleton had been fully researched, recorded in 3D and "all the elements of the skeleton will be made available for the public to research".
"We strongly hope that the new owner, whether it's an institution or private, will ensure that it's being seen by the public," he said.
"I've never seen a real-life fossil before ... It makes me feel in awe because it's quite majestic," said Lauren Lim, 33, who went to view the exhibit.
Gorgosaurus skeleton fetches more than $6m at auction
