Names

The synonymous name "Hydrobacteria" (hydro = "water") refers to the moist environment inferred for the common ancestor of those species. In contrast, species of Bacillati possess adaptations for life on land. Since 2024, the only validly published name for this group is kingdom Pseudomonadati (there used to be none, because no levels above phylum could exist in earlier versions of the Prokaryotic Code).