Published: Oct 21, 2010 4:06 PM EDT
Updated: Oct 21, 2010 1:09 PM EDT

VERO BEACH, Fla. (AP) - A fossil collector may have found a prehistoric bone with art work on it in Florida.

Last year, James Kennedy cleaned off a 15-inch bone he had found two years earlier. The lines on it looked like a four-inch etching of a walking mammoth with tusks.

University of Florida researchers examined the etching with an electron microscope. Their tests showed it was genuine.

The National Museum of Natural History examined it. The Smithsonian Institution's archaeologists copied and studied it.

The Smithsonian's Dennis Stanford specializes in North American archaeology. He said no evidence was found that it is a forgery. But, he says, the Smithsonian doesn't authenticate objects unless they are donated to the museum.

Kennedy is hoping to sell it.