[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 Rhizobiales Kuykendall 2006 see Order Hyphomicrobiales Douglas 1957 (Approved Lists 1980)
           Family Methylocystaceae Bowman 2006
             Genus Methylocystis (ex Whittenbury et al. 1970) Bowman et al. 1993
               Methylocystis echinoides (ex Gal'chenko et al. 1977) Bowman et al. 1993