Phylum [Vertebrata] (Lamarck, 1801)
Count: -
   Class Reptilia Linnaeus, 1758 - reptiles
  Count: 4o6f1g; †20o115f227g
     Subclass †Synapsida Osborn, 1903 - synapsids see Class Synapsida Osborn, 1903
    Count: [*] †2o21f23g
       Order †Pelycosauria Cope, 1878 - pelycosaurs
      Count: [*] †5f7g
         Family †Ophiacodontidae Nopsca, 1923
        Count: -
           Genus †Archaeothyris Reisz, 1972
          Count: -
           Genus †Ophiacodon Marsh, 1878
          Count: -