Remarkable fossils have more recently been found in the Gogo formation of northern Western Australia. This is a former Upper Devonian reef system, where well-preserved fossils of 25 species have been found. The relationship between the placoderm and other jawed fish is still not clear. Most placoderms were benthic predators, near the bottom of the water column. The largest types, such as "Dunkleosteus" and "Gorgonichthys" were 6 metre-long top predators in the middle and upper pelagic zones.