Description
Jumbo sized Stromatolite fossil from the fossil record of the Precambrian. These fossils are great educational & hands on learning specimens & come from North Africa near the Sahara desert. Stromatolites or stromatoliths are layered mounds, columns, & sheet-like sedimentary rocks that were originally formed by the growth of layer upon layer of cyanobacteria, a single-celled photosynthesizing microbe. Fossilized stromatolites provide records of ancient life on Earth. Lichen stromatolites are a proposed mechanism of formation of some kinds of layered rock structure that are formed above water, where rock meets air, by repeated colonization of the rock by endolithic lichens. Stromatolites are layered bio-chemical mounds formed in shallow water by the trapping, binding & cementation of sedimentary grains by microbial mats of microorganisms, especially cyanobacteria. They exhibit a variety of forms & structures, or morphologies, including conical, stratiform, branching & columnar types. Stromatolites occur widely in the fossil record of the Precambrian, Very few ancient stromatolites contain fossilized microbes. While features of some stromatolites are suggestive of biological activity. They peaked about 1.25 billion years ago & subsequently declined in abundance & diversity so that by the start of the Cambrian they had fallen to 20% of their peak. The most widely supported explanation is that stromatolite builders fell victim to grazing creatures (the Cambrian substrate revolution, this theory implies that sufficiently complex organisms were common over 1 billion years ago. stromatolite Fossil Larger Ancient Earth Life 1 Billion Years 2Inch Dh83
