Dunkleosteus Prehistoric Fish - Essay Example

The characteristic of this genus classified it with the Placodermi, the group of armored prehistoric fish that started to appear during the Silurian period and perished during the transformation between Devonian to the Carboniferous. The genus Dunkleosteus is in the order Arthrodita and the family of Dinichthyidae.

            The Gnathostomata became the dominant organisms during the Devonian Period. Their primary difference to other vertebrates is their vertical biting device or the jaws which “consist of an endoskeletal mandibular arch and a wide variety of exoskeletal grasping, crushing, or shearing organs” including the teeth and the jaw bones (Janvier 2). The living organisms in this classification include sharks, rays, chimaeras, ray-finned fishes, and land vertebrates.

            The clade of Placodermi is now in extinction because of the incapacity of the organisms to survive. The Placoderm are characterized by the presence of dermal armor comprising head armor and thoracic armor. Their thoracic armor is distinct because the foremost dental plates form a ring around the body and include one median dorsal plate (Janvier 3).   

            The order Anthrodita is comprised of organisms in Placodermi which have movable joints between the armor surrounding the head and the body. The organisms belonging to this class are also distinct for their two sets of upper tooth plates, gnathic plates which are tuberculated, and large endocrinal postorbital process (Janvier 4). These structures allow the lower jaw to move down while the head shield also budges for a large opening.

            Together with their extinctions of these prehistoric armored fish, their primary characteristics of having armors which cover their entire head and some of their body. The functional jaws of the placoderms have become an obvious feeding advantage and are now a primary feature of all many fish.