10.7" Stromatolite (Greysonia) From Bolivia - Pre-Cambrian
This is a beautiful and well defined, polished slabs of Stromatolites (Greysonia sp) from the Miraflores Formation of Bolivia. They are Vendian (Pre-Cambrian) in age or approximately 650 million years old. One side is nicely polished while the back has been left in a natural/rough state. The width varies up to 1 1/2" thick and it comes with an acrylic display stand.
These oxygen producing cyanobacteria were so simple they lacked DNA packaging nucleus, but were responsible for possibly the largest changes the earth has undergone. They were the only major source of atmospheric oxygen critical for the development of more complex life.