Pteraspidomorpha - Cyathaspidiformes
Parent taxon: Heterostraci according to R. van der Laan 2019
See also Elliott 2016, Elliott 2013, Long 2011 and Nelson et al. 2016
Sister taxa: Amphiaspidiformes, Aporemaspis, Ariaspididae, Aserotaspis, Cardipeltida, Cardipeltidae, Cardipeltiformes, Ceraspidae, Corvaspidida, Corvaspidiformes, Cyathaspida, Drepanaspidae, Guerichosteidae, Lepidaspidida, Lepidaspidiformes, Munchoaspis, Olbiaspidida, Palaeaspidi, Protaspidae, Psammolepis, Psammosteiformes, Pteraspidi, Pteraspidiformes, Rimasventeraspis, Strosipherus, Tesseraspidida, Tesseraspidiformes, Tolypelepidida, Tolypelepidiformes, Toombsaspis, Traquairaspidida, Traquairaspidiformes, Kiangsuaspis, Yoglinia, Poriferaspis, Schizosteus, Pionaspis, Alainaspis, Anatolepsis, Pilolepsis, Irregulariaspis, Ennosviaspis, Steinaspis, Grumantaspis, Karelosteus, Listraspis, Asketaspis, Clydonaspis, Allocryptaspis, Corveolepis, Palaeodus, Obliaspis, Athenaegis, Strophisterus, Gunaspis, Homaspidella, Dyreaspis, Aspidosteus, Seretaspis, Pycnaspis, Archodus
Subtaxa: Cyathaspididae Cyathaspidoidei Hibernaspidoidei Siberiaspidoidei
Ecology: