Position in a system
| system | Vitae - living organisms |
| domain | Bacteria (Haeckel, 1894) Woese, Kandler Wheelis, 1990 - bacterians |
| phylum | Cyanobacteria Stanier ex Cavalier-Smith, 2002 - blue-green algae |
| class | Cyanophyceae Schaffner, 1909 |
| Cyanophyceae incertae sedis | |
| genus | Siphonophycus Schopf 1968 † |
| species | Siphonophycus robustum (Schopf) Knoll et al. † |