After Carroll, 1988

<==o †Protorothyrididae [monophyly questionable]
   |-- †Anthracodromeus
   |-- †Archerpeton
   |-- †Brouffia Carroll & Baird, 1972; U.Carb. CEu.
   |--o †Cephalerpeton
   |  `-- †C. ventriarmatum Moodie, 1912
   |-- †Coelostegus Carroll & Baird, 1972; U.Carb. CEu.
   |-- †Hylonomus lyelli Dawson, 1860 [Fritschia]
   `-- †Protorothyris archeri Price, 1937 [Melanothyris]

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