[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990 stat. inval. see Domain Bacteria Woese et al. 2024
     Phylum "Proteobacteria" Garrity et al. 2005 stat. inval. see Phylum Pseudomonadota Garrity et al. 2021
       Class Alphaproteobacteria Garrity et al. 2006
         Order Rickettsiales Gieszczykiewicz 1939 (Approved Lists 1980)
           Family Holosporaceae Görtz and Schmidt 2006
             Genus Holospora (ex Hafkine 1890) Preer and Preer 1982 nom. illeg. see Genus Holospora (ex Hafkine 1890) Gromov and Ossipov 1981
               1 Holospora undulata (ex Hafkine 1890) Preer and Preer 1982 see Holospora undulata (ex Hafkine 1890) Gromov and Ossipov 1981
               2 Holospora caryophila (ex Preer et al. 1974) Preer and Preer 1982
               3 Holospora elegans (ex Hafkine 1890) Preer and Preer 1982
               4 Holospora obtusa (ex Hafkine 1890) Preer and Preer 1982 see Holospora obtusa (ex Hafkine 1890) Gromov and Ossipov 1981