I checked with a paleontologist who grew up in Maine. He told me no coprolites have ever been found in Maine. There are no formations in Maine that yield such fossils. Whatever it is, and despite the appearance, it is extremely unlikely that they are coprolites.
Maybe someone at the Maine State museum could ID it for you or try the University of Maine.
I can certainly understand why people here are suggesting coprolites. Maybe you have a first!