Protopteraspis is an extinct genus of jawless fish known from fossil finds in North America, Europe and Australia. It lived from the Late Silurian to the Early Devonian. The animal's somewhat flat build has led some to believe that it was a bottom dweller, living in freshwater areas. It has been described as "somewhat unspecialized". Its snout was round and narrow, shorter than that of its immediate relatives. Protopteraspis also did no tpossess the horns found on the headshields of other pterapsids; rather, it had small points behind the gill opening. It did possess a medium-sized dorsal spine. Plates covering the headshield had ridges of dentine. It is theorized that the headshield formed in youth and that it grew via growth of the plates, which fused in adulthood. The scales of the anim