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, Cardipeltida, Cardipeltidae, Cardipeltiformes, Ceraspidae, Corvaspidida, Corvaspidiformes, Cyathaspididae, Cyathaspidiformes, Drepanaspidae, Lepidaspidida, Lepidaspidiformes, Olbiaspidida, Palaeaspidi, Protaspidae, Psammolepis, Psammosteiformes, Pteraspidi, Pteraspidiformes, Strosipherus, Tesseraspidida, Tesseraspidiformes, Thelodontidae, Tolypelepidida, Tolypelepidiformes, Traquairaspidida, Traquairaspidiformes
Subtaxa: Cyathaspidei Homalaspidella Irregulareaspis Poraspidei
Ecology: