Brachydeiroidea
 Brachydeiroidea is a superfamily of small to moderately large-sized arthrodire placoderms from the Late Devonian of Europe and Eastern North America.Brachydeiroids have in cross section a highly compressed body a pointed sometimes highly elongated snout and tremendous orbits. The plates of the trunk shield are noticeably shortened: in Synauchenia the trunk shield and head shield are fused together as a single immovable unit.