Thrombolites

I had the privilege to see these 2000 year old 'rocks'. Ancient forms of microbial communities that photosynthesise. They obtain calcium carbonate from the water to form these structures.
600 million years ago the ancestors of thrombolites and stromatolites produced the oxygen needed for life on land to exist!
I am in awe!
This is in Western Australia, Yalgorup National Park.