Base on recently reconstruction of Dunkleosteus terrelli by Ferron et al. 2017.
They noted their lifestyle was similar to that of a pelagic shark and adjusted the body morphology to suit.
And natural state to show Dunkleosteus as close mouth is rare in pleo-art.
Actually the self-sharpening fang and blade edge jaw is perfectly closure when it don't open the mouth.
So now is more natural, realistic and update reconstruction to show in here.