Chelicerata Heymons, 1901
   †Chasmataspidida Caster & Brooks, 1956
     Family †Diploaspididae Størmer, 1972
       1 Genus †Achanarraspis Anderson, Dunlop & Trewin, 2000
       2 Genus †Diploaspis Størmer, 1972
       3 Genus †Dvulikiaspis Marshall, Lamsdell, Shpinev & Braddy, 2014
       4 Genus †Forfarella Dunlop, Anderson & Braddy, 1999
       5 Genus †Heteroaspis Størmer, 1972
       6 Genus †Loganamaraspis Tetlie & Braddy, 2004
       7 Genus †Nahlyostaspis Marshall, Lamsdell, Shpinev & Braddy, 2014
       8 Genus †Octoberaspis Dunlop, 2002
       9 Genus †Skrytyaspis Marshall, Lamsdell, Shpinev & Braddy, 2014