Domain Eucaryota
   Subdomain Chlorota Doweld (2001)
     Kingdom Euglenobiota Leedale ex Doweld (2001)
       Subkingdom Percolobiotina Doweld, 2001
         Phylum Nucleariozoa Mikrjukov, 2000 [monotypic]
           Class Nucleariatea Doweld, 2001 [monotypic]
             Order Nucleariida Cavalier-Smith, 1993
               Family Nucleariidae Cann & Page, 1979
                 Genus Nuclearia Cienkowski, 1865