<==o SYNAPSIDA
   |--o CASEASAURIA
   |  |-- †Eothyrididae
   |  `-- †Caseidae
   `--o EUPELYCOSAURIA
      |-- †Varanopseidae
      `--+-- †Ophiacodontidae
         `--+-- †Edaphosauridae
            `--o SPHENACODONTIA
               |-- †Haptodus garnettensis
               `--+-- †Palaeohatteria
                  `--+-- †Pantelosaurus
                     `--+-- †Cutleria
                        `--o SPHENACODONTOIDEA
                           |-- †Sphenacodontidae
                           `-- THERAPSIDA (nisäkäsmäiset synapsidit)

Reference(s):

Carroll, R. L., 1988: Vertebrate paleontology and evolution.
–W. H. Freeman and company, New York, 1988, 698

Carroll, R. L., 1988: Appendix. 594-648.
in Carroll, R. L. 1988: Vertebrate paleontology and evolution.
–W. H. Freeman and company, New York, 1988, 698.