Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925
   Opisthokonta Cavalier-Smith, 1987 - opisthokonts see Clade Opisthokonta Cavalier-Smith 1987, nom. cl. inval.
     Metazoa Haeckel 1874 - multicellular animals see Kingdom Animalia Linnaeus, 1758
       Eumetazoa Bütschli, 1910 - eumetazoans
         Triploblastica see [unranked] Bilateria Hatschek, 1888
           Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
             Protostomia Grobben, 1908 see Infrakingdom Protostomia Grobben, 1908
               Ecdysozoa Aguinaldo, Turbeville, Linford, Rivera, Garey, Raff & Lake 1997, nom. cl. inval. - ecdysozoans see Clade Ecdysozoa Aguinaldo, Turbeville, Linford, Rivera, Garey, Raff & Lake 1997 [Lake, Halanych, Servin & Garey 2020]
                 Hemocoelia
                   Superphylum Panarthropoda Nielsen, 1995 see [unranked] Panarthropoda Nielsen, 1995
                     Phylum Tardigrada Doyère, 1840 - tardigrades
                       Class Heterotardigrada Marcus, 1927 - armored tardigrades
                         Genus Megastygarctides McKirdy et al., 1976
                           Megastygarctides orbiculatus McKirdy et al., 1976