After Okulitch, 1955

<==o †Ajacicyathida Bedford & Bedford, 1939 (nom. transl. Okulitch, 1943 pro Ajacicyathina Bedford & Bedford, 1939)
   |--o †Ajacicyathidae Bedford & Bedford, 1939
   |  |--o †Ajacicyathus Bedford & Bedford, 1939 [Ventriculocyathellus Vologdin, 1931 (nomen nudum?); Archaeocyathellus Simon, 1939 (non Ford, 1873)] L.Camb. NA. Eu. As. Aust.
   |  |  |-- †A. ajax (Taylor, 1910) [Archaeocyathus ajax Taylor, 1910]
   |  |  `-- †A. nevadensis (Okulitch)
   |  |--o †Archaeocyathellus Ford, 1873 (non Simon, 1939) [Protocyathus Ford, 1878] L.Camb. NA. Eu. As. Aust.
   |  |  |-- †A. rensselaericus Ford, 1873
   |  |  `-- †A. floreus Bedford & Bedford
   |  |--o †Densocyathus Vologdin, 1937; M.Camb. NCAs.
   |  |  `-- †D. sanachtycolensis Vologdin, 1937
   |  |--o †Nevadacyathus Okulitch, 1943; L.Camb. SWNA.
   |  |  `-- †N. septaporus (Okulitch, 1935) [Archaeocyathus septaporus Okulitch, 1935]
   |  |--o †Orbicyathus Vologdin, 1937; M.Camb. CAs.
   |  |  `-- †O. mongolicus Vologdin, 1937
   |  |--o †Pluralicyathus Okulitch, 1950 [pro Polycyathus Vologdin, 1928 (non Duncan, 1876)] M.Camb. As.
   |  |  `-- †P. heterovallum (Vologdin, 1928)
   |  |--o †Septocyathus Vologdin, 1937 [=? Ajacicyathus Bedford & Bedford, 1939] M.Camb. As.
   |  |  `-- †S. pedaschenkoi Vologdin, 1937
   |  |--o †Tumulocyathus Vologdin, 1937; M.Camb. NCAs.
   |  |  |-- †T. pustulatus Vologdin, 1937
   |  |  `-- †T. admirabilis Vologdin
   |  `--o †Urcyathus Vologdin, 1940; M.Camb. As.
   |     `-- †U. asteroides Vologdin, 1940
   |--o †Dictyocyathidae Taylor, 1910
   |  |--o †Dictyocanthus Born., 1891 [Alphacyathus Bedford & Bedford, 1939] L.-M.Camb. Eu. As. Aust.
   |  |  |-- †D. tenerimus Born., 1891
   |  |  `-- †D. simplex Taylor
   |  |--o †Dokidocyathus Taylor, 1910; L.Camb. Aust.
   |  |  `-- †D. simplicissimus Taylor, 1910
   |  `--o †Spirillicyathus Bedford & Bedford, 1937 [Spiralicyathus Bedford & Bedford, 1937]; L.Camb. Aust.
   |     `-- †S. tenusi Bedford & Bedford, 1937
   |--o †Bicyathidae Vologdin, 1933
   |  |--o †Bicyathus Vologdin, 1933; M.Camb. As..
   |  |  `-- †B. ertaschkensis Vologdin, 1933
   |  `--o †Vacuocyathus Okulitch, 1950 [pro CoelocyathusVologdin, 1933 (non Sars, 1857)]; M.Camb. EEu. WAs.
   |     `-- †V. kidrjassovensis (Vologdin, 1933)
   |--o †Ethmophyllidae Okulitch, 1943
   |  |--o †Ethmophyllum Meek, 1868 [Beltanacyathus Bedford & Bedford, 1936; Zonacyathus Bedford & Bedford, 1937; ?Leptosocyathus Vologdin, 1937] L.Camb. NA. Eu. As. Aust.
   |  |  `-- †E. whitneyi Meek, 1868
   |  |--o †Ethmocyathus Bedford & Bedford, 1934; L.Camb. Aust.
   |  |  `-- †E. lineatus Bedford & Bedford, 1934
   |  |--o †Ethmocoscinus Simon, 1939; L.Camb. Aust.
   |  |  `-- †E. papillipora (Bedford & Bedford, 1934) [Coscinocyathus papillipora Bedford & Bedford, 1934]
   |  |--o †Thalamocyathus Gordon, 1920 [Cyclocyathus Vologdin, 1931; Bronchocyathus Bedford & Bedford, 1936]; L.Camb. Eu. As. Aust. Ant.
   |  |  `-- †T. trachealis (Taylor, 1910) S.D. Simon, 1939 [Archaeocyathus trachealis Taylor, 1910]
   |  |--o †Cadniacyathus Bedford & Bedford, 1937; L.Camb. Aust.
   |  |  `-- †C. asperatus Bedford & Bedford, 1937
   |  |--o †Annulocyathus Vologdin, 1940; M.Camb. NCAs.
   |  |  `-- †A. pulcher Vologdin, 1940
   |  |--o †Clathrocyathus Vologdin, 1932; M.Camb. NCAs.
   |  |  `-- †C. firmus Vologdin, 1932
   |  |--o †Tercyathus Vologdin, 1932; M.Camb. NCAs.
   |  |  |-- †T. duplex Vologdin, 1932
   |  |  `-- †T. altaicus Vologdin
   |  |--o †Leptosocyathus Vologdin, 1937 [Leptocyathus Vologdin, 1937]; M.Camb. As.
   |  |  `-- †L. curviseptum Vologdin, 1937
   |  `--o †Sajanocyathus Vologdin, 1937; M.Camb. NCAs.
   |     `-- †S. ussovi Vologdin, 1937
   `--o †Coscinocyathidae Taylor, 1910
      |--o †Coscinocyathus Born., 1884 [Coscinoptycha Taylor, 1910; Tuvacyathus Vologdin, 1937] L.-M.Camb.
      |  |-- †C. tuba S.D. Ting, 1937
      |  `-- †C. cornucopiae Born.
      |--o †Coscinocyathellus Vologdin, 1937 [Formosocyathus Vologdin, 1937; Ethmocoscinus Simon, 1939]; M.Camb. NCAs.
      |  `-- †C. parvus Vologdin, 1937
      |--o †Carinacyathus Vologdin, 1932 [Stillicidocyathus Ting, 1937; Salairocyathus Vologdin, 1940; Sigmocyathus Bedford & Bedford, 1936]; M.Camb. NCAs.
      |  `-- †C. loculatus Vologdin, 1932
      |--o †Dictyocoscinus Bedford & Bedford, 1936; L.Camb. Aust.
      |  `-- †D. beltanum Bedford & Bedford, 1936
      |--o †Polycoscinus Bedford & Bedford, 1937 [=? Coscinocyathus Born., 1884] L.Camb. Aust.
      |  `-- †P. contortum Bedford & Bedford, 1937
      |--o †Pycnoidocoscinus Bedford & Bedford, 1936: L.Camb. Aust.
      |  `-- †P. pycnoideum Bedford & Bedford, 1936
      |--o †Tabulacyathus Vologdin, 1932 [Tabulocyathus Vologdin, 1937; Putapacyathus Bedford & Bedford, 1936] L.-M.Camb. Aust. NCAs.
      |  `-- †T. taylori Vologdin, 1932
      `--o †Asterocyathus Vologdin, 1940 [Coscinocyathus Born., 1884] M.Camb. CAs. NCAs.
         `-- †A. dentatus (Vologdin, 1938) [Coscinocyathus dentatus Vologdin, 1938]

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