The largest species, D. terrelli, measuring up to 10 metres (33 Ft.) and weighing 3.6 tonnes (4.0 short tons), was a hypercarnivorous apex predator. Few other placoderms, save, perhaps, its contemporary,Titanichthys, rivaled Dunkleosteus in size.
Dunkleosteus is a pachyosteomorph arthrodire originally placed in the family Dinichthyidae, a family composed mostly of large, carnivorous arthrodires like Gorgonichthys. Anderson (2009) suggests that because of its primitive jaw structure Dunkleosteus should be placed outside the family Dinichthyidae, perhaps close to the base of the clade Pachyosteomorpha, near Eastmanosteus. Carr and Hlavin (2010) resurrect Dunkleosteidae and place Dunkleosteus, Eastmanosteus and a few other genera from Dinichthyidae within it (Dinichthyidae, in turn, is made into a monospecific family).
Temporal range: Late Devonian, 380–360Ma
Reconstructed skull, Queensland Museum
Found in Wiki
A is heterostius in the same order as a dunkleosteus.