Millerosteus

Millerosteus is an extinct genus of coccosteid arthrodire placoderm from the Early Givetian stage of the Middle Devonian period. Fossils are found in Orkney and Caithness, Scotland. It was a small placoderm with an body length of 14 cm. Millerosteus is one of the few arthrodires known from specimens preserving the entire skeleton.

Phylogeny
Millerosteus is a member of the family Coccosteidae, which belongs to the clade Coccosteomorphi, one of the two major clades within Eubrachythoraci. The cladogram below shows the phylogeny of Millerosteus: