what is the oldest fossil terrestrial
Cyanobacteria: Fossil Record. The cyanobacteria have an extensive fossil record. The oldest known fossils, in fact, are cyanobacteria from Archaean rocks of western Australia, dated 3.5 billion years old. This may be somewhat surprising, since the oldest rocks are only a little older: 3.8 billion years old! Cyanobacteria are among the easiest microfossils to recognize.