Pteraspidomorpha - Cyathaspida
Full reference: J. Kiaer. 1932. The Downtonian and Devonian vertebrates of Spitsbergen. IV, Suborder Cyathaspida. Skrifter Om Svalbard Og Ishavet 52:1-26
Parent taxon: Heterostraci according to J. Kiaer 1932
See also Loeffler and Dineley 1976
Sister taxa: Amphiaspidiformes, Aporemaspis, Ariaspididae, Aserotaspis, Cardipeltida, Cardipeltidae, Cardipeltiformes, Ceraspidae, Corvaspidida, Corvaspidiformes, Cyathaspidiformes, Drepanaspidae, Guerichosteidae, Lepidaspidida, Lepidaspidiformes, Munchoaspis, Olbiaspidida, Palaeaspidi, Protaspidae, Psammolepis, Psammosteiformes, Pteraspidi, Pteraspidiformes, Rimasventeraspis, Strosipherus, Tesseraspidida, Tesseraspidiformes, Tolypelepidida, Tolypelepidiformes, Toombsaspis, Traquairaspidida, Traquairaspidiformes, Kiangsuaspis, Anatolepsis, Homaspidella, Yoglinia, Corveolepis, Palaeodus, Obliaspis, Seretaspis, Listraspis, Pionaspis, Archodus, Athenaegis, Asketaspis, Schizosteus, Pycnaspis, Strophisterus, Irregulariaspis, Gunaspis, Karelosteus, Grumantaspis, Poriferaspis, Steinaspis, Alainaspis, Ennosviaspis, Clydonaspis, Aspidosteus, Pilolepsis, Allocryptaspis, Dyreaspis
Subtaxa: Cyathaspidei Homalaspidella Poraspidei
Ecology: