Pteraspidomorpha - Psammosteiformes
Parent taxon: Heterostraci according to S. V. Moloshnikov 2009
Sister taxa: Amphiaspidiformes, Aporemaspis, Ariaspididae, Cardipeltida, Cardipeltidae, Cardipeltiformes, Ceraspidae, Corvaspidida, Corvaspidiformes, Cyathaspida, Cyathaspidiformes, Drepanaspidae, Guerichosteidae, Lepidaspidida, Lepidaspidiformes, Munchoaspis, Olbiaspidida, Palaeaspidi, Protaspidae, Psammolepis, Pteraspidi, Pteraspidiformes, Rimasventeraspis, Strosipherus, Tesseraspidida, Tesseraspidiformes, Thelodontidae, Tolypelepidida, Tolypelepidiformes, Toombsaspis, Traquairaspidida, Traquairaspidiformes
Subtaxa: Obrucheviidae Pycnosteidae
Ecology:
Distribution:
• Devonian of Belarus (1 collection), Canada (1: Nunavut), Estonia (7), Latvia (2), the Russian Federation (4)
Total: 15 collections including 19 occurrences