what are the oldest known animal fossil
In short, the animals didn't evolve much, he saidâsuggesting that, at least for its roughly 200 million years of existence, Otavia was built to last. The new oldest-animal study is detailed in the current issue of the South African Journal of Science. A scanning electron microscope view of Otavia antiqua.
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!