After Carroll, 1988, and Reisz, 2005, with species from “The Paleobiology Database”

<==o †Caseidae Williston, 1911
   |?- †Phreatophasma aenigmaticum Efremov, 1954
   |--o †Angelosaurus Olson & Beerbower, 1953
   |  |-- †A. dolani Olson & Beerbower, 1953
   |  |-- †A. greeni Olson, 1962
   |  `-- †A. romeri Olson & Barghusen 1962
   |--o †Casea Williston, 1910
   |  |-- †C. broilli Williston, 1910
   |  |-- †C. halselli Olson, 1954
   |  |-- †C. nicholsi Olson, 1954
   |  `-- †C. rutena Sigogneau-Russel & Russell, 1974
   |--o †Caseopsis Olson, 1962
   |  |-- †C. agilis Olson, 1962
   |  `-- †C. sp. cf. C. agilis
   |--o †Cotylorhynchus Stovall, 1937
   |  |-- †C. bransoni Olson & Barghusen, 1962
   |  |-- †C. hancocki Olson & Beerbower, 1953
   |  `-- †C. romeri Stovall, 1937a
   |-- †Ennatosaurus tecton Efremov, 1956
   |-- †Caseoides sanangelensis Olson & Beerbower, 1953
   `-- †Oromycter dolesorum Reisz, 2005; L.Perm. CNAm.

Reference(s):

Special thanks to:

Jos H. M. Dols, for gathering additional information and species of these animals.