Dicksonosteus

Dicksonosteus is an extinct genus of basal arthrodire, placoderm fish, which lived during the Early Devonian period of Spitsbergen, Norway. "Dicksonosteus" was once considered an actinolepid, but is now grouped within the family Phlyctaeniidae.
Description.
"Dicksonosteus" is considered basal to the arthrodires, the most successful and widespread group of placoderms during the Devonian period notable for the movable joint between armor surrounding their heads and bodies. Its body is wide and flat, and unlike the more robust-jawed arthrodires that would come after it, such as "Dunkleosteus" and "Coccosteus", its jaws were relatively feeble, suggesting the lifestyle of a benthic fish that subsisted primarily on smaller, softer-bodied animals. Exceptionally preserved specimens of "Dicksonosteus" from Spitsbergen, Norway display details of its braincase and internal anatomy, the details of which have been described.How?