Pterichthys
a genus of Placoderms, discovered by Hugh Miller in the Old Red Sandstone. The head and anterior part of the trunk were defended by a buckler of large ganoid scales, united by sutures, the cuirass articulating at the sides with a back plate; the rest of the body covered with small ganoid scales. Pectorals long and wing-like, a scaly short tail. Twelve species; eight from the lower, and four from the Upper Devonian of Orkney, Cromarty, Caithness, Scotland, and in Ireland.