The Devonian was a time of wonder and mystique. The Age of Fishes, it capped the rise of vertebrates and heralded the rise of skeletal diversity. Fish in this age began to inch towards the shore; some would have crawled through the muck of it; some others still out of the water.
But before the Carboniferous rolled in, with its skeleton-enhanced fish, giant insects, and great plants, the Devonian paid heed to a relatively diverse group of “fish,” the placoderms, by giving us the “hinge necked” fish, the Arthrodira. Placoderms are relatively simple looking, with a generally scaly body, simple fins, and a large head fashioned into a sort of shield. The mouth has become enhanced with a bony core for the mandible, otherwise a fleshy-flap within which lay a cartilage framework, and its margin was developed into a variety of shapes, including prongs, saws, or a relatively smooth edge. But amongst the greatest of arthrodires was Dunkelosteus which, along with other giants like Titanichthys, Dinichthys, Eastmannosteus, formed a cadre of super fishes, most of whom were predators (Titanichthys being considered a filter feeder; see Janvier, 1998). Their jaws arranged into an elaborate system of sawing edges, their maws must have been utterly terrifying had we, us wee unarmored humans, ever seen them in the flesh.