Wikipedia
Dunkleosteus is an extinct genus of arthrodire placoderm fish that existed during the Late Devonian period, about 360–380 million years ago. Some of the species, such as D. terrelli, D. marsaisi, and D. magnificus, are among the largest arthrodire placoderms ever to have lived.
The largest species, D. terrelli, measuring up to long and in weight, 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, 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).
New studies have revealed several features in both its food and biomechanics, as well as its ecology and physiology. Placodermi first appeared in the Silurian, and the group became extinct during the transition from the Devonian to the Carboniferous, leaving no descendants. The class persisted in the fossil record for at least 70 million years, in comparison to the 400-million-year-long history of sharks.
In recent decades, Dunkleosteus has achieved recognition in popular culture, with a large number of specimens on display, and notable appearances in entertainment media like Sea Monsters - A Walking with Dinosaurs Trilogy and River Monsters. Numerous fossils of some species have been found in North America, Poland, Belgium, and Morocco. The name Dunkleosteus combines the Greek osteus (οστεος), meaning "bone", and Dunkle, in honor of David Dunkle of the Cleveland Museum of Natural History.