After Parker, 1982

<==o Spirostreptida
   |--o Cambalidea
   |  |-- Cambalidae
   |  |-- Cambalopsidae
   |  `-- Iulomorphidae
   |--o Epinannolenidea
   |  |-- Pseudonannolenidae
   |  |-- Epinannolenidae
   |  |-- Physiostreptidae
   |  |-- Choctellidae
   |  `-- Pericambalidae
   `--o Spirostreptidea
      |--o Spirostreptoidea
      |  |-- Spirostreptidae
      |  `-- Harpagophoridae
      `--o Odontopygoidea
         |-- Odontopygidae
         |-- Atopogestidae
         `-- Adiaphorostreptidae

Reference(s):