Cyanobacteria

The oldest fossils ever found are Cyanobacteria, dated about 3.5 billion years old. Cyanobacteria are photosynthetic, single-celled aquatic organisms. They are often referred to as the blue-green algae, even though algae has a nucleus in contrast to cyanobacteria. When cyanobacteria colonizes it forms stromatolites. Stromatolites are chalky rock-like mounds built-up of layers of cyanobacteria and trapped sediment. This is where the oldest cyanobacteria fossils were originally found, in Australia.

Cyanobacteria gets its name from its bluish-green pigment. Cyan is color mix between blue and green. "Cyanobacteria" literally means bluish-green bacteria. It's colorful pigment assists in capturing light for photosynthesis. Cyanobacteria has been a huge factor in "shaping the course of evolution and ecological change throughout earth's history." During the Archaean and Proterozoic Eras, Cyanobacteria that formed impacted the oxygen atmosphere that humans depend on today. Cyanobacteria also had a tremendous affect on plants. Plants' chloroplasts are actually cyanobacterium living within their cells. Scientists believe this happened through the process of endosymbiosis.

Work Cited:

1. Cyanobacteria: Fossil Record. (n.d.). Fossil Record of the Cyanobacteria. Retrieved September 23, 2014, from http://www.ucmp.berkeley.edu/bacteria/cyanofr.html
2. Introduction to the Cyanobacteria. (n.d.). Introduction to the Cyanobacteria. Retrieved September 23, 2014, from http://www.ucmp.berkeley.edu/bacteria/cyanointro.html
3. Cyanobacteria: Life History and Ecology. (n.d.). Life History and Ecology of Cyanobacteria. Retrieved September 23, 2014, from http://www.ucmp.berkeley.edu/bacteria/cyanolh.html