The drawing known as “Head of a Bear” was sketched on a square piece of pale, pink-beige paper measuring just less than 3 inches. The piece is believed to have been drawn around 1480.

Estimated to be more than 500 years old and just 2.75 by 2.75 inches, the drawing known simply as "Head of a Bear" will likely be sold for $11 million to $16.5 million, the auction house said.