T. rex could become most expensive fossil ever – but it’s a ​problem for scientists

In 1997, Sotheby’s hosted its first natural history auction selling fossils and other wonders of our prehistoric world.

It was a niche event mostly attended by the world’s museums looking for specimens to add to their collections.

On the books that day was a Tyrannosaurus Rex called Sue – she was eventually sold for $8m (£6m) to the Field Museum in Chicago.

Nearly 30 years later, on Tuesday, another T. rex will make an appearance at the annual auction – one of the most complete