Largest Stegosaurus Fossil Ever Found Set for Auction at Sotheby's

The 150-million-year-old specimen, named 'Apex,' could fetch up to $6 million in July sale.

Discovered in Colorado, 'Apex' measures 11 feet tall and 20 feet long.
The fossil is 30% larger than the previous record-holder, 'Sophie,' in London.
Auctioning fossils stirs debate over private ownership versus scientific access.
The buyer receives 3D scan data to encourage research and educational use.
Exhibition of 'Apex' will be open to the public in New York before the auction.