Astraspida
 Astraspida or astraspids are a small group of fossil armored fossil jawless vertebrates which lived in the Middle Ordovician (about 450 million years ago) in North America. They are placed among the Pteraspidomorphi because of the large dorsal and ventral shield of their head armor. They are represented by a single genus Astraspis including possibly two species A. desiderata and A.