I am very familiar with snakeheads (channa sp.) and am certain this is not the remains of one. Most snakeheads have a broader, flatter head and mouth structure.
Also does not appear to be a bowfin, (Amiva calva), Another fish I am very familiar with. Bowfin typically have more numerous teeth but slightly smaller. Also they have smaller eyes that are located more forward and higher up on the head. And Bowfin have numerous boney plates on their head and skull. The LMR is not the type of environment that Bowfin occur in either, they prefer heavily vegetated slow moving swamp / marsh type environments.
I agree that it is most likely a Saugeye / sauger not only from the appearance but also because I have caught them from the LMR regularly.
Does kind of look like someone filleted that fish though.