After Parker, 1982 [slightly modified after Martin & Davis, 2001]

<==o Cyclopoida Burmeister, 1834 (kyklooppiäyriäiset)
   |?- Ascidicolidae Torell, 1860 [from Martin & Davis, 2001, not recognized by Parker, 1982]
   |?- Buproridae Thorell, 1859 [from Martin & Davis, 2001, not recognized by Parker, 1982]
   |?- Chordeumiidae Boxshall, 1988
   |?- Cucumaricolidae Bouligand & Delamare-Deboutteville, 1959 [from Martin & Davis, 2001, not recognized by Parker, 1982]
   |?- Fratiidae Ho, Conradi & López-Conzález, 1998
   |?- Mantridae Leigh-Sharpe, 1934 [from Martin & Davis, 2001, not recognized by Parker, 1982]
   |?- Ozmanidae Ho & Thatcher, 1989
   |?- Speleoithonidae da Rocha & Iliffe, 1991
   |?- Thaumatopsyllidae Sars, 1913 [from Martin & Davis, 2001, not recognized by Parker, 1982]
   |-- Oithonidae Dana, 1852
   |-- Cyclopinidae Sars, 1913
   |-- Cyclopidae Dana, 1846
   |-- Clausidiidae Embleton, 1901
   |-- Lichomologidae
   |-- Oncaeidae Giesbrecht, 1893
   |-- Corycaeidae Dana, 1852
   |-- Sapphirinidae Thorell, 1860
   |-- Archinotodelphyidae Lang, 1949
   |-- Artotrogidae Brady, 1880
   `-- Asterocheridae Giesbrecht, 1899

Reference(s):