Turtle ID, New Jersey (1 Viewer)

I took this photo yesterday in Princeton, NJ, and I'm not sure about the species: https://www.flickr.com/photos/tremarctos/16934828817/. Eastern Painted Turtles are by far the most common species around here, and I don't recall ever seeing one with an all-black head (but I haven't paid much attention to them). Is it a melanistic individual of that species, or something else? It was quite large relative to nearby Painted Turtles.

Although I'm from the "old world" , I woud say, this is a Northern Red-bellied Turtle, Pseudemys rubriventris

I agree with Mario - Redbelly Turtle. If the shell was wet, we might have had another field mark to go on - some dark red markings. But the all black head is fairly distinctive, too. My field guide says "... melanism is almost universal among large adults in some areas, notably in southern New Jersey."