Beyrichiida
(tree size 20)
Drepanelloidea
(tree size 76)
Eridostraca
(tree size 15)
Leiocopa
Paraparchitocopa
Aparchitoidea
(tree size 19)
Beyrichioidea
(tree size 10)
Eurychilinoidea
(tree size 12)
Oepikelloidea
Primitiopsoidea
(tree size 34)
Tetradelloidea
(tree size 69)
Beyrichiacea
Drepanellacea