Subphylum [Vertebrata] Cuvier, 1812 - vertebrates
   Class Agnatha Cope, 1889
     Subclass †Thelodonti Kiaer, 1932
       Order †Loganelliiformes Turner, 1991
         Family †Loganelliidae Karatajūtė-Talimaa, 1997
           Genus †Illoganellia Märss, Wilson & Thorsteinsson, 2002 [monotypic]
             1 †Illoganellia colosseaᵀ Märss, Wilson & Thorsteinsson, 2002