Pteraspidomorpha - Traquairaspidida
Parent taxon: Heterostraci according to E. J. Loeffler and D. L. Dineley 1976
Sister taxa: Amphiaspidiformes, Aporemaspis, Ariaspididae, Aserotaspis, Cardipeltida, Cardipeltidae, Cardipeltiformes, Ceraspidae, Corvaspidida, Corvaspidiformes, Cyathaspida, Cyathaspidiformes, Drepanaspidae, Guerichosteidae, Lepidaspidida, Lepidaspidiformes, Munchoaspis, Olbiaspidida, Palaeaspidi, Psammolepis, Psammosteiformes, Pteraspidi, Pteraspidiformes, Rimasventeraspis, Strosipherus, Tesseraspidida, Tesseraspidiformes, Tolypelepidida, Tolypelepidiformes, Toombsaspis, Traquairaspidiformes, Clydonaspis, Homaspidella, Seretaspis, Karelosteus, Pilolepsis, Archodus, Poriferaspis, Grumantaspis, Obliaspis, Schizosteus, Listraspis, Irregulariaspis, Dyreaspis, Corveolepis, Pycnaspis, Yoglinia, Ennosviaspis, Allocryptaspis, Anatolepsis, Steinaspis, Strophisterus, Gunaspis, Kiangsuaspis
Subtaxa: none
Ecology: planktonic suspension feeder
Distribution: found only at Pressure Point, Somerset Island [Peel Sound Fm] (Silurian of Nunavut)