In a new finding scientists have discovered the signature of microscopic life on rocks from 300 million years earlier than any previously known such fossils.
The signature is known as a microbially induced sedimentary structure (MISS). Even today the MISS forms in pools having stagnant water along the lakes and rivers. It can also be found in the muck of coastal mud flats.
In the moist environment the complex communities of microorganisms form layers of slimy life and over time the microbial mat etches the graffiti into rock due to sedimentation and that again turns into stone. The MISS fossils have visible polygonal cracks and gas domes having tell-tale microscopic features.
Lead author of the study Nora Noffke said, “The structures give a very clear signal on what the ancient conditions were, and what the bacteria composing the biofilms were able to do.”
Noffke is from Old Dominion University and her finding is published in the Astrobiology journal. She and her colleagues mapped the community to millimeter scale from the Pilbara district of western Australia, the region that claims having more of such paleontological fame in its fossilized stromatolites.
The Stromatolites are like large rocky mushrooms and microscopic life has constructed it by trapping sediments. These rocks once dominated the ancient seashores, but now are available only in few locations. Shark Bay in western Australia is one of the locations. Here the fossilized MISS also exists along with the ancient stromatolites