After Carroll, 1967, Laurin & Reisz, 1997, Lee & Spencer, 1997, and Kissel, 2010

<==o †Diadectomorpha Watson, 1917
   |--o †Limnoscelidae Williston, 1911
   |  |--o †Limnoscelis Williston, 1911; L.Perm. SWNAm.
   |  |  |-- †L. paludis Williston, 1911
   |  |  `-- †L. dynatis Berman & Sumida, 1990
   |  |--o †Limnosceloides Romer, 1952; L.Perm. SWNAm.
   |  |  |-- L. dunkardensis Romer, 1952
   |  |  `-- L. brachycoles Langston, 1966
   |  |-- †Limnoscelops longifemur Levis & Vaughn, 1965; L.Perm. SWNAm.
   |  |-- †Limnostygis relictus Carroll, 1967, L.Carb. NENAm.
   |  `?- †Romeriscus periallus Baird & Carroll, 1967 [nomen dubium sensu Laurin & Reisz, 1992]
   `--+?- †Tseajaia campi Vaughn, 1964 [Tseajaiidae]
      `--o †Diadectidae
         |?- †Stephanospondylus pugnax (Geinitz & Deichmueller, 1882) Stappenbeck, 1905 [Phanerosaurus pugnax Geinitz & Deichmueller, 1882]
         |-- †Ambedus pusillus Kissel & Reisz, 2004
         `--+-- †Oradectes  sanmiguelensis (Lewis & Vaughn, 1965) Kissel, 2010 [Diadectes sanmiguelensis Lewis & Vaughn, 1965] [Validity of Oradectes qustionable due publiciation in Thesis]
            `--+-- †Orobates pabsti Berman, Henrici, Kissel, Sumida, & Martens, 2004 [Diadectidae genera et species indet. (Berman & Henrici, 2003)] L.Perm. CEu.
               `--+--o †Desmatodon case, 1908
                  |  |-- †D. hollandi Case, 1908
                  |  `-- †D. hesperis Vaughn, 1969
                  `--+-- †Silvadectes absitus (Berman et al., 1998) Kissel, 2010 [Diadectes absitus Berman et al., 1998] [Validity of Silvadectes qustionable due publiciation in Thesis]
                     `==o †Diadectes Cope, 1878 [Nothodon Marsh, 1878; Empedocles Cope, 1878; Helodectes Cope, 1880; Empedias Cope, 1883; Chilonyx Cope, 1883; Bolbodon Cope, 1896; Diadectoides Case, 1911; Animasaurus Case & Williston, 1912]
                        |-- †D. lentus (Marsh, 1878)
                        |-- †D. sideropelicus Cope, 1878
                        |-- †D. tenuitectus Cope, 1896
                        |-- †D. carinatus (Case & Williston, 1912)
                        `-- †Diasparactus zenos Case, 1910


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