Phylum Chordata Bateson, 1885 - chordates
   Class †Conodonta Eichenberg, 1930
     Subclass †Conodonti Branson see Subclass Conodonta Eichenberg, 1930
       Order †Ozarkodinida Dzik
         Family †Polygnathidae Bassler
           Genus †Polygnathus Hinde, 1879
             †"Polygnathus semicostatus group"
               †Polygnathus paraobliquicostatus