A recent study published in the journal Palaeontologia Electronica raises concerns about the impact of private collectors on Tyrannosaurus rex fossil research. The study found that commercial fossil collecting has walled off so many T. rex fossils from scientific research that it has severely hindered the scientific record. Of the 141 scientifically useful T. rex fossils known to exist, 71 specimens are in private or commercial hands, while 61 are held in public trust, such as museums. This indicates that more scientifically valuable specimens are currently held by private owners or commercial entities than by public institutions.
Since the early 1990s, commercial interests have collected more Tyrannosaurus rex fossils than public trusts did in nearly a century and a half, discovering nearly 2.4 times more specimens than public institutions during this period.
The growing market for dinosaur fossils is reflected in the record prices at auctions, such as the $31.8 million sale of Stan, one of the most complete T. rex skeletons. Scientists have concluded that the market has depleted the scientific record of T. rex because vertebrate fossils that are not in public trusts are unavailable for scientific study, with only 11% of commercially harvested T. rex fossils ending up in public trusts, according to Live Science.
"It is dispiriting and exasperating," said Thomas Carr, a Tyrannosaurus rex researcher and director at the Carthage Institute of Paleontology in Wisconsin, according to News18. Carr noted that the private ownership of juvenile and subadult T. rex specimens is especially worrisome, as these represent the least understood growth stages and make up 20 percent of privately held T. rex fossils.
"The early growth stages of T. rex are bedeviled by a poor fossil record, and so the loss of them carries the heaviest scientific cost. At the current moment, our knowledge of one of the most basic aspects of T. rex biology is frustratingly compromised by market interests," said Carr.
Scientists warn that the private trade in Tyrannosaurus rex specimens is hindering scientific efforts to study the Cretaceous predator, which roamed Earth for roughly 80 million years—from 145 million to 66 million years ago. The trade in T. rex fossils is depriving paleontologists of data regarding the giant lizard's variation across its growth stages and its geological distribution.
According to the study, fewer Tyrannosaurus rex fossils are available for scientific research as wealthy collectors continue to purchase them for private collections, raising concerns among scientists. The high prices of Tyrannosaurus rex fossils, which have become art pieces since the auction of 'Sue' in 1997, prevent most museums from acquiring them. Scientists wrote, "T. rex fossils are sold for millions of dollars, making them available only to the richest people or consortia," putting them far out of reach for most museums unless a philanthropic donor steps in.
"My hope is that concerned colleagues will start counting up, and publishing on, the specimens of the species that they study that are lost to the commercial market," said Carr, according to Live Science.
"So far, none of the privately owned T. rex fossils have been donated to, or offered for purchase to a public trust, by a private estate," wrote Carr, according to Gizmodo. Defenders of the market argue that fossils often end up in museums eventually, but Carr's data suggests otherwise: only a tiny fraction of privately held T. rex fossils are ever donated or sold to public institutions.
Without access to these specimens, scientists cannot build a reliable picture of how T. rex grew, matured, or even whether the species showed sexual dimorphism (differences between males and females). According to previous teams, a sample size of 70 to 100 specimens of adult nonavian dinosaurs is required to measure the likelihood of sexual dimorphism in a population with a high degree of certainty.
Even if researchers once studied a fossil, its scientific value drops if future teams can't access it, limiting ongoing research and discoveries. "This is a major problem because in science, replicability is everything," Carr noted. "If a fossil is locked in a collector's mansion or a storage unit, other scientists can't study it, which hampers research and confirmation of findings."
The article was written with the assistance of a news analysis system.