Parent taxon: Pteraspidomorpha according to R. Van Der Laan 2019
See also Blieck et al. 2002, Bryant 1932, Dineley and Metcalf 1999, Elliot and Loeffler 1989, Elliott 2016, Elliott and Ilyes 1996, Elliott and Swift 2010, Gadow 1898, Hay 1902, Jaekel 1911, Jordan 1963, Loeffler and Dineley 1976, Long 2011, Nelson et al. 2016 and Ritchie and Gilbert-Tomlinson 1977
Sister taxa: Arandaspida, Astraspida
Subtaxa: Amphiaspidiformes Aporemaspis Ariaspididae Cardipeltida Cardipeltidae Cardipeltiformes Ceraspidae Corvaspidida Corvaspidiformes Cyathaspida Cyathaspididae Cyathaspidiformes Drepanaspidae Lepidaspidida Lepidaspidiformes Olbiaspidida Palaeaspidi Protaspidae Psammolepis Psammosteiformes Pteraspidi Pteraspidiformes Strosipherus Tesseraspidida Tesseraspidiformes Thelodontidae Tolypelepidida Tolypelepidiformes Traquairaspidida Traquairaspidiformes