Nanotyrannus was initially mistaken for a juvenile Tyrannosaurus rex.
But it wasn't small. Its weight has been estimated at 900 to 1,500 kilograms and its length at around three metres.
Now, an assembled skeleton of the dinosaur has been sold at Sotheby's auction house in New York. It fetched 47.4 million dollars, equivalent to approximately 470 million Swedish kronor.
The sale comes amid a debate in the scientific community about whether dinosaur skeletons should be sold privately or displayed to the public.
In July, Sotheby's sold a Tyrannosaurus rex for $50.1 million, a record.