Stromatolites are living organisms, mainly cyanobacteria, which need shallow water to thrive. They are sedimentary structures made up of alternating layers of organic-rich and organic-poor materials and with that the first fossil record of life.
Originally uploaded in Integrating Research and Education:Montana Geoheritage Project:Montana-Yellowstone Geologic Field Guide Database.
Image 182100 is a 505 by 1500 pixel WebP
Uploaded: Apr7 18