life see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Arthropoda Siebold, 1848 - arthropods
     Class Arachnida Lamarck, 1801
       Micrura Hansen & Sørensen, 1904
         Megoperculata Börner, 1902
           Tetrapulmonata Shultz, 1990
             Order Araneae Clerck, 1757 - spiders see Suborder Araneae Clerck, 1757
               Suborder Opisthothelae Pocock, 1892 - modern spiders see Infraorder Opisthothelae Pocock, 1892
                 Araneomorphae Smith, 1902 see [unranked] Araneomorphae Smith, 1902
                   Neocribellatae Caporiacco
                     Araneoclada
                       Entelegynae Simon, 1893
                         canoe tapetum clade
                           Orbiculariae Walckenaer, 1802
                             Superfamily Araneoidea Clerck, 1757
                               derived araneoids
                                 reduced piriform clade
                                   araneoid sheet web weavers
                                     spineless femur clade
                                       theridioids
                                         1 Family Nesticidae Simon, 1894
                                         2 Family Theridiidae Sundevall, 1833 - cobweb and widow spiders