Procaryotic Genera Domain "Bacteria" Woese et al. 1990 Phylum Actinobacteria Garrity and Holt 2001 [monotypic] Class Actinobacteria Stackebrandt et al. 1997 Subclass Sphaerobacteridae Stackebrandt et al. 1997 [monotypic] 1 Order Sphaerobacterales Stackebrandt et al. 1997 [monotypic]