Chelicerata Heymons, 1901
†Eurypterida Burmeister, 1843 - eurypterids
†Eurypterina Burmeister, 1843
1 Superfamily †Onychopterelloidea Lamsdell, 2011 [monotypic]
2 Superfamily †Moselopteroidea Lamsdell, Braddy & Tetlie, 2010 [monotypic]
3 Superfamily †Megalograptoidea Caster & Kjellesvig-Waering, 1955 [monotypic]
4 Superfamily †'Eurypteroidea' Burmeister, 1843 [monophyletic?]
5 †Diploperculata Lamsdell, Hoşgör & Selden, 2013