Children (19 direct children, 146 direct and indirect children):
Psammosteidae
(tree size 6)
Aserotaspis
Tolypelepidida
(tree size 4)
Pteraspidiformes
(tree size 33)
Cyathaspidiformes
(tree size 30)
Pycnosteidae
(tree size 1)
Traquairaspidiformes
(tree size 9)
Cyathaspidida
(tree size 37)
Tesseraspidiformes
(tree size 1)
Cardipeltiformes
(tree size 2)
Weigeltaspididae
(tree size 1)
Corvaspididae
(tree size 3)
Ariaspididae
Ceraspidae
Drepanaspidae
Psammosteiformes
Olbiaspidida
Amphiaspidiformes
Traquairaspidida