Modern classification of prokaryotic rRNA are Archaea, bacteria, eukarya. Deeply branching bacteria. They are believed to be similar to earlier existing bacteria. Example is aquifex Phototrophic bacteria. Contains photosynthetic lamellae, most are autotrophically divided into five groups based on pigments; ? Blue-green bacteria (cyanobacteria) ? Green sulfur bacteria ? Purple nonsulfur ? Purple sulfur bacteria ? Green nonsulfur bacteria ? Cyanobacteria