living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Prokaryotae see Superkingdom Prokarya
     Kingdom Monera Haeckel 1866 see Domain Bacteria Woese et al. 1990
       Division Bacteria (Haeckel 1894) see Domain Bacteria Woese et al. 1990
         "Rickettsias" see Order Rickettsiales Gieszczykiewicz 1939 (Approved Lists 1980)
           Order Chlamydiales Storz and Page 1971 (Approved Lists 1980)
             Genus Chlamydia Jones et al. 1945 (Approved Lists 1980)
               Chlamydia psittaci (Lillie 1930) Page 1968 (Approved Lists 1980) see Chlamydophila psittaci (Lillie 1930) Everett et al. 1999
               Chlamydia trachomatis (Busacca 1935) Rake 1957 (Approved Lists 1980)