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 brevilaminus Branson & Mehl