Named By: Jaekel - 1911
Classification: Chordata, Placodermi, Arthrodira, Brachythoraci, Coccosteina, Brachydeiroidea, Brachydeiridae.
Species: O. rostratus (type), O. magnus.
Size: Skulls of O. rostratus about 11-13 centimetres long, Skulls of O. magnus about 18 centimetres long.
Known locations: Poland.
Time period: Frasnian of the Devonian.
Fossil representation: Mostly skulls, but some partial post cranial remains.
Oxyosteus is a genus of arthrodire placoderm fish that lived in the waters of Easterrn Europe during the late Devonian. Oxyosteus had a flattened body and an elongated snout. The eyes would have been relatively large in comparison to the size of the skull, indicating that Oxyosteus was probably a visually orientated predator. So far two species have been assigned to the genus, of which O. magnus was slightly larger.