Work continues at the construction site of the World Trade Center ground zero area which was the site of one of the Sept. 11 terrorist attacks, in New York, Wednesday, July 24, 2002. Nearby, hundreds of people flocked to Federal Hall on Wednesday for the opening of an exhibit of historical photos and potential future plans for the site.(AP Photo/Suzanne Plunkett)
Work continued at the construction site of the World Trade Center ground zero area which was the site of one of the Sept. 11 terrorist attacks, in New York, Wednesday, July 24, 2002.
SUZANNE PLUNKETT/AP

The ship that was uncovered 22 feet below the ruins of the World Trade Center four years ago has finally been identified as a ‘Hudson River Sloop,’ or a Dutch ship designed to navigate shallow water. And just who identified the mysterious ship? Oh, you know, your average group of tree ring scientists.

Samples from the ship were analyzed by Columbia University tree ring scientists who determined the wood from the vessel originated from Philadelphian White Oak trees, chopped down in 1773.

Dario Martin-Benito of Columbia’s Tree Ring Lab told “Live Science”:

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“Philadelphia was one of the most — if not the most —important shipbuilding cities in the U.S. at the time. And they had plenty of wood so it made lots of sense that the wood could come from there.”

The scientists say the same type of trees might have been used to build parts of Independence Hall (where the Declaration of Independence and the US Constitution were signed.)

Archaeologists also found other interesting 18th century artifacts during the excavation of the World Trade Center including ceramic dishes, bottles, shoes and animal bones.

According to Live Science, there are still some mysteries surrounding the discovered sloop:

Historians still aren’t certain whether the ship sank accidently or if it was purposely submerged to become part of a landfill used to bulk up Lower Manhattan’s coastline. Oysters found fixed to the ship’s hull suggest it at least languished in the water for some time before being buried by layers of trash and dirt.