I took this to a local vet this morning. He said it was without a doubt, a possum. There is discoloration on the teeth that repesent where the gum was at. Even considering that, it still had a a very unsual set of teeth.
It has been suggested that perhaps these fangs are fake. I want to assure everyone that I have much better things to do with my time, than to spend it inside the mouth of a dead possum. The way I photographed this is exactly the way I found it.