Leading US palaeontologists are calling for a worldwide halt to the sale of vertebrate dinosaur fossils. The booming market for specimens, driven by their popularity with wealthy private collectors, including Hollywood stars, is pushing up prices and putting them out of reach of museums and scientists, they say.

While the art market is organised around brand-name artists, dinosaur sales are all about celebrity species, with a tyrannosaurus rex skeleton fetching up to $10m, although the velociraptor is the most prized. The price tag for a triceratops’s skull is $170,000 to $400,000, and a diplodocus is $570,000 to $1.1m. Last year a complete egg of an aepyornis maximus, otherwise known as an elephant bird, sold for $130,000 – roughly five times what it would have gone for a decade earlier.

Jerry Smith, an expert in the evolution of freshwater fishes in the department of zoology at Michigan University, told the Observer: “When specimens go into a private home or collection, our understanding, interpretation or discovery of new information they contain will never reach the scientific community.”

Last year the US Society of Vertebrate Palaeontology (SVP) called on the Parisian auction house Aguttes to cancel a sale inside the Eiffel tower that contained just one lot: a 29-foot-long dinosaur of a yet-to-be identified species. The winning bidder paid $2.3m for the piece.

Executive members of the society drew attention to the claim that the winning bidder could name the species, calling that assertion “misleading because the naming of new species is governed by the rules of the International Code of Nomenclature”.

“The sale of all fossils is inappropriate,” says Catherine Badgley, former president of the SVP, which represents more than 2,200 international palaeontologists. “Many, particularly vertebrate fossils, are rarely common, and it’s certainly not the case for dinosaurs. The commodification is in principle inappropriate because it motivates unscrupulous people.”

Facebook Twitter Pinterest Nicolas Cage. Photograph: Sascha Steinbach/Getty Images

As ARTnews magazine pointed out last week, we can thank Steven Spielberg’s 1993 film Jurassic Park for the surging dinosaur market. The initial phase peaked in 1997, just months after the film’s sequel, The Lost World, was released, when a 12m-long T rex named Sue was sold at Sotheby’s for a record-breaking $8.36m to the Field Museum in Chicago.

But the interest has hardly abated. The recent Art Basel Miami included a special project called DeXtinction, organised by two mining companies, Avant Mining and Interprospekt, that included a 120 million-year-old mother and juvenile allosaur and a well-preserved dinosaur egg set from the Cretaceous period, 75 million years ago.

According to the New York Post’s Page Six column, the exhibit drew the attention of Leonardo DiCaprio, who along with Nicolas Cage and Russell Crowe, has staked out a reputation as a collector.

And that’s what alarms palaeontologists who fear not only the loss of scholarship but also the diminution of appreciation for the work that goes into discovery, excavation and reconstruction of a dinosaur skeleton as they become fashionable objects of home decor.

Dinosaur fossil collection comes with risks. In 2013, the 67 million-year-old skull of a tyrannosaurus bataar bought by Nicolas Cage became the focus of an investigation into smuggling. Cage had bought it at an auction in California, beating DiCaprio with a $276,000 bid. It was later discovered that the skull was obtained from Eric Prokopi, a self-described “commercial palaeontologist” who had previously pleaded guilty to illegally importing fossils from Mongolia and China.

The looted skull was ultimately returned to Mongolia.

All of which still serves to alarm working palaeontologists, who express concern that institutions are being priced out of the market and important specimens lost to private collections. Badgley points to specimens dug from the Green River Formation in Colorado, Wyoming and Utah, which has some of the earliest bataar fossil specimens known. “Bat fossils overall are extremely rare, and even if half from this really early period are going into private collections, then that’s an enormous amount of really important information that’s being lost,” she says.

Badgley’s message to collectors, then, is simple: collect by all means but steer clear of unique specimens.

“There isn’t a strong link between expensive trophy specimens and an increase in the science of palaeontology. If anything, they’re seen more for their rarity and economic value than for their scientific information. It’s not necessary for people to become interested in palaeontology by having a unique specimen that’s theirs and theirs alone.”

In her experience, she says, “people are often just as happy with something that’s very common”.