some species after Kröger & Mapes, 2005, and Kröger & Mapes, 2007

<==o †Pseudorthoceratoidea Flower & Caster, 1935 sensu Engeser, 1998 [Pseudorthocerataceae Flower & Caster, 1935 (nom. transl. Sweet, 1964 ex Pseudorthoceratidae Flower & Caster, 1935]
   |?- †Elmoceras graffhami Kröger & Mapes, 2007
   |?- †Hesperoceras Miller & Youngquist, 1947
   |?- †Stiloceras Zhuravleva, 1978
   |--o †Carbactinoceratidae Schindewolf, 1943
   |  `--o †Carbactinoceras Schindewolf, 1943
   |     |-- †C. torleyi Schindewolf, 1943
   |     |-- †C. aliense Chen, 1981
   |     |-- †C. fayettevillense (Croneis, 1926) [Rayonnoceras fayettevillense Croneis, 1926]
   |     |-- †C. giganteum Liang & Wang, 1991
   |     |-- †C. insulare (Foord, 1897) [Orthoceras insulare Foord, 1897]
   |     |-- †C. procerum Kröger & Mapes, 2007
   |     `-- †C. protentum Gordon, 1965
   |--o †Pseudactinoceratidae Schindewolf, 1943
   |  |-- †Pseudactinoceras
   |  |-- †Macroloxoceras Flower, 1957
   |  |-- †Berganoceras Flower, 1939
   |  |?- †Rayonnoceras solidiformes Croneis, 1926
   |  `--o †Campyloceras McCoy, 1844
   |     |-- †C. unguis (Phillips, 1836) [Orthoceras unguis Phillips, 1836]
   |     |-- †C. arcuatum (Phillips, 1836) [Orthoceras arcuatum Phillips, 1836]
   |     |-- †C. novosemelicum Shimansky, 1996
   |     |-- †C. striatulum (Kröger & Mapes, 2004) [Mooreoceras striatulum Kröger & Mapes, 2004]
   |     `-- †C. imoense (Kröger & Mapes, 2004) [Mooreoceras imoense Kröger & Mapes, 2004]
   `--o †Pseudorthoceratidae Flower & Caster, 1935 emend. Flower, 1939
      |--o †Pseudorthoceras Girty, 1911 emend. Kröger & Mapes, 2004
      |  `-- †P. knoxense (McChesney, 1859) [Orthoceras knoxensis McChesney, 1859; Pseudorthoceras knoxense (McChesney) Girty, 1911, 1915; Kröger & Mapes, 2004]
      |--o †Mitorthoceras Gordon, 1960 emend. Kröger & Mapes, 2005
      |  |-- †M. perfilosum Gordon, 1960 [taxonomic history]
      |  `-- †M. crebriliratum (Girty, 1909) [taxonomic history]
      `--+--o †Hebestorthoceras Kröger & Mapes, 2005
         |  |-- †H. unicamera (Smith, 1938) [Orthoceras unicamera Smith, 1938]
         |  |-- †H. indianum (Girty, 1909)
         |  |-- †H. tricamera (Smith, 1938)
         |  |-- †H. brokenarrowense Kröger & Mapes, 2005
         |  `?- †H.? caneyanum (Girty, 1909)
         |-- †Aidaroceras Doguzhaeva, 2002
         |-- †Bitaunioceras Shimizu & Obata, 1936
         `-- †Shikanoceras Shimansky, 1954

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