Ostracoderms lit.shell-skins are the armored jawless fish of the Paleozoic Era. The term does not often appear in classifications today because it is paraphyletic excluding jawed fishes may also be polyphyletic if anaspids are closer to cyclostomes and thus does not correspond to one evolutionary lineage. However, the term is still used as an informal way of loosely grouping togethe. Webostracoderm, an archaic and informal term for a member of the group of armoured, jawless, fishlike vertebrates that emerged during the early . WebIntroduction Ostracoderms shell-skinned are of several groups of extinct, primitive, jawless fishes that were covered in an armour of bony plates. They appeared in the Cambrian, . Web de may. de Ostracoderms are an extinct, paraphyletic grouping of jawless fishes that were characterized by a bizarre diversity of bony head shields. They were the most important vertebrates for nearly million . WebThe vertebrate integument arose about million years ago as an armour of dermal bony pl