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, Psammosteiformes, Pteraspidi, Pteraspidiformes, Rimasventeraspis, Strosipherus, Tesseraspidida, Tesseraspidiformes, Tolypelepidida, Tolypelepidiformes, Toombsaspis, Traquairaspidida, Traquairaspidiformes, Kiangsuaspis, Pilolepsis, Ennosviaspis, Grumantaspis, Poriferaspis, Schizosteus, Irregulariaspis, Seretaspis, Pycnaspis, Dyreaspis, Obliaspis, Corveolepis, Steinaspis, Anatolepsis, Strophisterus, Yoglinia, Homaspidella, Archodus, Clydonaspis, Karelosteus, Gunaspis, Listraspis, Allocryptaspis
Subtaxa: Amphiaspidoidei Cyathaspididae Cyathaspidoidei Hibernaspidoidei Siberiaspidoidei