A Tyrannosaurus rex fossil billed as one of the world’s largest and most complete specimens was sold for a record US$50.1 million on Tuesday to a mystery bidder. Sotheby’s said the 67-million-year-old fossil, nicknamed “Gus,” is the most expensive set of dinosaur bones ever auctioned off, besting th

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.

A Tyrannosaurus rex skeleton from South Dakota, nicknamed Gus, has become the world’s most expensive fossil sold at auction.