After Froehlich, 2002, and Badiola, Astibia, Pereda Suberbiola & Murelaga, 2002

<==o †Pachynolophidae Pavlow, 1888
   |?- †“Hyracotherium” sp.1 [=? †“Hyracotherium” seekensi]
   |--o †Plagiolophinae Remy, 1976
   |  |--o †Leptolophus Remy, 1965
   |  |  |-- †L. stehlini Remy, 1965
   |  |  |-- †L. nouleti (Stehlin, 1904)
   |  |  `-- †L. magnus Remy, 1998
   |  `--o †Plagiolophus Pomel, 1847 [Paloplotherium]
   |     |-- †P. mazateronensis Cuesta, 1994
   |     |-- †P. minor
   |     |-- †P. fraasi
   |     `-- †P. annectens
   `--o †Pachynolophinae Pavlow, 1888
      |-- †Anchilophus depereti Gervais, 1852
      `--o †Pachynolophus Pomel, 1847
         |-- †P. duvali Pomel, 1847
         `-- †P. livinierensis

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