Pteraspidoidei Pteraspidiformes

1 pteraspidoidei

1.1 pteraspididae
1.2 gigantaspididae
1.3 protaspididae

pteraspidoidei

restoration of larnovaspis

pteraspidoidei contains more derived taxa within pteraspidiformes, though, protopteraspidids, such doryaspis , panamintaspis, share various features these derived pteraspidids.

pteraspididae

pteraspididae devonian-aged family contains stereotypical, torpedo-shaped pteraspidids, such type genus, pteraspis, , close relatives errivaspis , rhinopteraspis, popularly thought have actively swam in water column. elongated rostral plate thought hydrodynamic ability. various genera found in various marine , estuarine strata of devonian europe , north america.

gigantaspididae

gigantaspididae monogeneric family erected gigantaspis, genus of pteraspidids restricted devonian marine strata of svalbard. species of gigantaspis superficially resemble genera of sister taxon, protaspididae, i.e., had armor shaped hot bun or round loaf of bread.

protaspididae

protaspididae family of bun or bread loaf-shaped pteraspidids found in devonian marine strata rocky mountains of united states, , of europe. genera, such xylaspis , woodfjordaspis, similar in form gigantaspis, while others, such protaspis , tuberculaspis, have armor more mound-shaped, or psephaspis, compressed form described psammosteid closely related drepanaspis.