Where are archaebacteria most commonly found?

Answer by  Corwin (38)

Archaebacteria (or more correctly, Archae) contribute up to 20% of the Earth's biomass, but if you're just looking for a common example, go with the ocean. Plankton are Archae.

Answer by  MinnieBannister (44)

Archaea (the modern name) were first discovered in hot springs and salty environments, but have now been found in soil and aquatic environments. There are methane generating (methanogen) archaea which are commensal with man and animals, particularly ruminants and termites, which digest cellulose. You find the methanogens living anaerobically in swamps as well. Plankton have commensal archaea. They're everywhere!