not single-cell fossils fossil record oldest known forms of life on the planet http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html University of California Museum of Paleontology Precambrian cherts http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html Fossil Record of the Bacteria 3.5 BILLION years http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html Bacteria: Fossil Record. http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html Berkeley university page http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html Fossil Record http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html for bacteria http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html fossil record http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html fossil record http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html fossils http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html not single-cell fossils http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html for bacteria single-celled organisms - cyanobacteria http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html oldest known fossils http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html billions http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html Fossil Record of the Bacteria http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html thick cell walls http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html at 3.5 billion years ago http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html bacteria