Skeleton, which stands 3.8 meters tall and measures about 11.6 meters long, sold Tuesday at Sotheby's for $51 million; The sale has ignited a debate over the transfer of rare fossils into private hands of billionaires at the expense of museums, scientific research

Palaeontologists warn before auction at Sotheby’s in New York that super-rich collectors are harming research

Private buyers are increasingly outbidding museums for fossils. That’s making it difficult—or even impossible—for researchers to improve our understanding of the past.