Arachnida Lamarck, 1801
   1 Order Amblypygi Thorell, 1883 - whip spiders
   2 Order Uropygi Thorell, 1882 - whip scorpions see [unranked] Uropygi Thorell, 1882
   3 Order Schizomida Petrunkevitch, 1945 - schizomids
   4 Order Palpigradi Thorell, 1888 - palpigrades
   5 Order Ricinulei Thorell, 1876 - ricinuleids
   6 Order Solifugae Sundevall, 1833