Last year, resort workers in Brewster, Mass., set out to dig a walkway on the beach and in the process stumbled upon an unexpected find. Although it wasn’t what most would consider buried treasure, researchers were excited about the six-foot across, 400-pound whale skull they unearthed.

My Fox Boston reports the skull, initially thought to be only about 30 years old, has now been found to pre-date even the early English settlers. The skull after it was carefully extracted and dried was given to Woods Hole Oceanographic Institute researchers who used carbon dating to determine its age as between 1500 and 1650.

Watch the My Fox Boston report with footage of the skull:

CBS Local out of Boston reports Brian Sharp from the International Fund for Animal Welfare, which coordinated removal of the skull, said it was “incredibly fragile” and took two days of digging to extract from the sand.

The whale bone will be put on display at the Smithsonian in Washington, D.C.

Watch a crane lift the skull last year in this YouTube video: