Phylum Cyanobacteria Garcia-Pichel et al. (2020) see Phylum Cyanobacteriota Oren et al. 2022
   Class Cyanophyceae Hauck (1885) see Class Chroococcophyceae Hollerbach et al. 1953
     Order Nostocales Borzì (1914) see Order Nostocales corrig. Borzì 1914
       Family Heteroscytonemataceae McGregor & Sendall (2018) [monotypic] see Family Heteroscytonemataceae McGregor and Sendall 2018
         1 Genus Heteroscytonema McGregor & Sendall (2018) see Genus Heteroscytonema McGregor and Sendall 2018