Gracilicutes (Latin: gracilis, slender, and cutis, skin, referring to the cell wall) is a taxon created by Cavalier-Smith, which he believes to be a clade comprising the Proteobacteria, the Planctobacteria (comprising Chlamydiae and Planctomycetes), the Sphingobacteria (comprising the green sulfur bacteria and Bacteroidetes), and Spirochaetae. It is a Gram-negative clade that branched off from other bacteria just before the evolutionary loss of the outer membrane or capsule, and just after the… (More on Gracilicutes)