Dunkleosteus belonged to a group of armoured fish called placoderms of the Devonian period. it is known for its large massive head, and its armour plated, Shark-like body. Inhabiting the seas of what are now North America, Poland, Belgium & Morocco, Dunkleosteus had sharp bony plates instead of tooth, its jaws could produce a bite force of up to 74000N (755kg), roughly equivalent to that of Tyrannosaurus, plus its jaws open and close less than half the time a guillotine would snap. It was the largest predator of its time with largest species, D. Terrelli reaching a length of around 10-12 meters and 1000 kg in weight larger than the size of a Great White Shark. Like its cousins, Titanichthys Clarki(Who was its filter-feeding cousin that rivaled it in size, also with a length of 8-12m. It was from Eastern North America, Europe & Morocco), Rhizodus(A Giant 7-meter Lobe-Finned Fish from Devonian-Carboniferous Kansas & Scotland), Saivodus(A 10m Ctenacanthiform Shark from Carboniferous-Mid Permian North America) & Helicoprion/Whorl-Tooth Chimaera(An ancient 8-12m Chimaeroid/Shark Relative from Permian North Asia, The Ural Mountains of Russia, Mexico, North America & Western Australia), it probably fed on smaller prey like other placoderms, temnospondyl amphibians & fishes while early sharks such as small Cladoselache & Stethacanthus was also present in its ecosytem. Dunkleosteus fossils have been found with bitemarks of others of its kind. placoderms as a group went extinct at the end of the Devonian.