CoccosteoideaCoccosteoidea is an extinct superfamily of arthrodire placoderms that lived during the Devonian period.Phylogenyis divided into the sister clades Pachyosteomorphi and Coccosteomorphi, the latter of which can be further sub-divided into the two sister superfamilies Coccosteoidea and Incisoscutoidea, as shown in the cladogram below: