Heritage Auctions of Dallas sold the Tyrannosaurus bataar specimen in an auction in New York Sunday to an anonymous bidder on the condition that the sale receive court approval, Fox News reported.
A temporary restraining order sought to prevent the sale of the skeleton, with court documents contending the specimen originated in Mongolia and that the export of fossils from that country is illegal under the country's law.
During the auction, a handful of Mongolians protested outside the venue.
"We want this dinosaur to go back to Mongolia where it belongs, that is the sole purpose of this," said Bolorsetseg Minjin, a Mongolian paleontologist and director of the Institute for the Study of Mongolian Dinosaurs, who was among those protesting.
Heritage Auctions said specimen entered the United States legally, and that "the consignors warranted in writing to Heritage that they hold clear title to the fossils."
Heritage Auctions has not identified the seller or the buyer.