Chordata Bateson, 1885 - chordates
   Class †Ostracophori
     Order †Anaspida Traquair - anaspids see Class Anaspida Traquair
       20 Family †Lasaniidae [monotypic] see Family Birkeniidae Traquair, 1899
       21 Family †Birkeniidae Traquair, 1899