Kingdom Protozoa Goldfuss, 1818 - protozoa
   Subkingdom Neozoa Cavalier-Smith, 1993 see Kingdom Protozoa Goldfuss, 1818
     Infrakingdom Neomonada Cavalier-Smith, 1997
       Phylum Neomonada Cavalier-Smith, 1997
         Subphylum Mesomycetozoa Herr, Ajello, Taylor, Arseculeratne & Mendoza, 1999
           Class Cristidiscoidea Page, 1987 see Kingdom Nucleariae Tedersoo, Sánchez-Ramírez, Kõljalg, Bahram, Döring, Schigel, May, Ryberg & Abarenkov, 2018
             Order Nucleariida Cavalier-Smith, 1993
               Genus Nuclearia Cienkowski, 1865