Pteraspidomorpha - Traquairaspidiformes
Parent taxon: Heterostraci according to R. Van Der Laan 2019
See also Long 2011 and Nelson et al. 2016
Sister taxa: Amphiaspidiformes, Aporemaspis, Ariaspididae, Cardipeltida, Cardipeltidae, Cardipeltiformes, Ceraspidae, Corvaspidida, Corvaspidiformes, Cyathaspida, Cyathaspidiformes, Drepanaspidae, Guerichosteidae, Lepidaspidida, Lepidaspidiformes, Munchoaspis, Olbiaspidida, Palaeaspidi, Protaspidae, Psammolepis, Psammosteiformes, Pteraspidi, Pteraspidiformes, Rimasventeraspis, Strosipherus, Tesseraspidida, Tesseraspidiformes, Thelodontidae, Tolypelepidida, Tolypelepidiformes, Toombsaspis, Traquairaspidida
Subtaxa: Phialaspididae Phialaspis Weigeltaspidae
Ecology:
Distribution:
• Devonian of Canada (1: Nunavut collection), the Russian Federation (2), Ukraine (4), the United Kingdom (10)
• Silurian of the United Kingdom (3)
Total: 20 collections including 23 occurrences