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, Ennosviaspis, Allocryptaspis, Pilolepsis, Schizosteus, Irregulariaspis, Archodus, Dyreaspis, Strophisterus, Karelosteus, Gunaspis, Homaspidella, Steinaspis, Anatolepsis, Listraspis, Poriferaspis, Grumantaspis, Kiangsuaspis, Obliaspis, Seretaspis, Pycnaspis, Corveolepis, Clydonaspis, Yoglinia
Subtaxa: Amphiaspidoidei Cyathaspididae Cyathaspidoidei Hibernaspidoidei Siberiaspidoidei
Ecology: planktonic suspension feeder