DUFFY is a sub-adult Tyrannosaurus rex. Stan Sacrison discovered DUFFY in 1993 and the Black Hills Institute excavated the skeleton in 1993, 1994, 1996 and 2006. Seventy-six bones and 49 loose, rooted teeth in total were recovered from the site, making the skeleton 25% complete. Many of the bones discovered were from the skull making the skull a remarkable ~70% complete. The dig site encompassed an area of about 55 x 70 feet.