Rhamphodopsis is a genus of extinct ptyctodont placoderm from the Middle Devonian Old Red Sandstone of Scotland.
Rhachiosteus pterygiatus is an extinct brachythoracid arthrodire placoderm from the Late Devonian of Germany. It is known only from a single specimen, which may be a larval or juvenile form, as the skull of said specimen is only 19 millimetres long.
Selenosteidae is a family of small to large-sized arthrodire placoderms from the Late Devonian. With the exception of the Chinese Phymosteus, selenosteids lived in shallow seas in what is now Eastern North America, Eastern Europe, and Northeastern Africa.
Draconichthys elegans is a selenosteid arthrodire placoderm from the Late Frasnian Kellwasserkalk facies of the Anti-Atlas Mountains of what is now Morocco. During the Late Devonian, the region would have been a shallow, algae-dimmed sea.
Selenosteus brevis is a large selenosteid arthrodire placoderm known from the Famennian Cleveland Shale of Ohio. Scrappy remains from the Frasnian Rhinestreet Shales of Erie County, New York, were attributed by Hussakof and Bryant to this genus in 1919, but, this identification is doubtful. A second species, S. kepleri, was described in 1901, but, not enough differences can be seen between its specimens, and those of the type species to warrant new species status.
Asterosteus is genus of rhenanid placoderm from the Eifelian. The type species, A. stenocephalus, is known from an incomplete skull from Middle Devonian strata of Ohio. What may be a second species is described from fragments decorated with star-shaped tubercules from the Eifelian-aged Gebze beds of Turkey.
Stenosteus is a genus of medium-sized selenosteid arthrodire placoderms known from the Upper Famennian Cleveland Shale of Ohio. Estimated skull lengths range from 6 to 9 centimeters
Gymnotrachelus hydei is a large selenosteid arthrodire placoderm known from the Late Famennian Cleveland Shale of Ohio. It was originally reconstructed as physically resembling Selenosteus, with slightly smaller orbits. Later specimens led to a reappraisal, and now G. hydei is thought to have a more gar-like or barracuda-like build.
Microsteus is a genus of small selenosteid arthrodire placoderms known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Germany.
Enseosteus is a genus of small selenosteid arthrodire placoderms known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Germany and Morocco.
Paramylostoma arcualis is an extinct selenosteid arthrodire placoderm from the Late Famennian Cleveland Shale of Late Devonian Ohio. It has a compressed, box-like head and thoracic armor, and large, rounded orbits. However, in comparison with other selenosteids, such as Selenosteus, P. arcualis' orbits were rather small. P. arcualis had smooth jaws that suggest the animal was durophagous.
Rhinosteus is a genus of small to medium selenosteid arthrodire placoderms known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Germany and Morocco.
Braunosteus schmidti is a medium-sized selenosteid arthrodire placoderm known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Bad Wildungen, Germany. B. schmidti has a broad skull about 9 centimeters long, and a short, but pointed rostrum. Its appearance is very similar to that of the basal selenosteid Pachyosteus.
Pachyosteus bulla is a medium-sized selenosteid arthrodire placoderm known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Bad Wildungen, Germany and from the Famennian portions of the Holy Cross Mountains of Poland. P. bulla has a broad skull about 7 to 10 centimetres long, a comparatively long median dorsal plate, and a short rostral plate that meets the pineal plate. In his cladogram, Rücklin (2011) regards P. bulla as a basal selenosteid, being the sister taxon of the American genera, and the Kellwasserkalk genera of Germany and Morocco.
Homostiidae is a family of flattened arthrodire placoderms from the Early to Middle Devonian. Fossils appear in various strata in Europe, Russia, Morocco, Australia, Canada and Greenland.
Walterosteus is a genus of small selenosteid arthrodire placoderms known from the Upper Frasnian Kellwasserkalk facies of Late Devonian Germany and Morocco.
Brachydeiridae is a family of small to moderately large-sized arthrodire placoderms from the Late Devonian of Europe, restricted primarily to the Kellwasserkalk Fauna of Bad Wildungen and Adorf.
Brachydeirus is a genus of small to moderately large-sized arthrodire placoderms from the Late Devonian of Europe, restricted to the Kellwasserkalk Fauna of Bad Wildungen and Adorf.
Oxyosteus is a genus of trout-sized, highly compressed arthrodire placoderms from the Late Devonian of Europe: The two described species are restricted to the Late Frasnian-aged Kellwasserkalk Fauna of Bad Wildungen, while a median dorsal plate of an unnamed species is known from the Middle Frasnian Holy Cross Mountains of Poland.
Synauchenia coalescens is a trout-sized, highly compressed arthrodire placoderm restricted to the Late Frasnian-aged Kellwasserkalk Fauna of Bad Wildungen.
