"Cyanobacteria are arguably the most successful group of microorganisms
<https://en.wikipedia.org/wiki/Microorganisms> on earth. They are the most
genetically diverse; they occupy a broad range of habitats across all
latitudes, widespread in freshwater, marine, and terrestrial ecosystems,
and they are found in the most extreme niches such as hot springs, salt
works, and hypersaline bays. Photoautotrophic
<https://en.wikipedia.org/wiki/Photoautotrophic>, oxygen-producing
cyanobacteria created the conditions in the planet's early atmosphere that
directed the evolution of aerobic metabolism and eukaryotic photosynthesis.
Cyanobacteria fulfill vital ecological functions in the world's oceans,
being important contributors to global carbon and nitrogen budgets." –
Stewart and Falconer[31]
<https://en.wikipedia.org/wiki/Cyanobacteria#cite_note-WalshSmith2011-31>