Chordata Bateson, 1885 - chordates
   Class †Ostracophori
     Order †Cycliae [monotypic]
       Family †Palaeospondylidae Stürtz, 1899 [monotypic] see Family Dipteridae Owen, 1846
         Genus †Palaeospondylus Traquair, 1890 [monotypic] see Genus Dipterus Sedgwick & Murchison, 1829
           1 †Palaeospondylus gunni see Dipterus valenciennesi Sedgwick & Murchison, 1828