The bones, wired together to keep them in place, were sold for $500 Tuesday. The winner bidder agreed to donate the skeleton to a forensics center for research.
Auctioneer Tim Richards found the skeleton among furniture and boxed items he collected from New Castle for the auction. The bones had apparently been someone's macabre decoration.
"'You won't believe what I found,"' Anita Mattingly, his fiancee, said he told her.
Tipton County Coroner Bob Nichols, after discussing the find with Richards, contacted University of Indianapolis forensic anthropologist Andrea Simmons, who examined the remains Friday.
Simmons concluded the skeleton was that of a European man who was between 5-foot-3 and 5-foot-5. Simmons told Mattingly the man died sometime before World War I and was not murdered.
Simmons suggested that the skeleton be donated to research instead of being used for a Halloween prop, but Richards already had advertised that it would be sold.
Jane Harper then made the purchase and donated it to the forensics laboratory at the University of Indianapolis.
"I just felt very strongly this person needed to be in a final resting place," Harper said.