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. Brachydeirids 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. The superficial anatomy of brachydeirids is extremely diverse, and each genus has been previously placed in their own monogeneric families.