Bacterial paleontology is rather young branch of paleontological studies. Bacteria and microbes in general could be perfectly preserved as fossils. The major part of the sedimentary rocks formed in the photic zone of epicontinental basins of the past originated under the influence of microorganisms. Studies have increased the number of minerals known to be formed with the participation of microorganisms to >100. Bacterial-paleontological data accompanied by the data on the first origin of eukaryotes, metazoans, etc. significantly enrich the knowledge of evolution of the biosphere and reveal a long period of transitional biosphere prior to the appearance of the typical eukaryotic biosphere of the modern type. The bacterial-paleontological data on carbonaceus chondrites make a foundation for the possibility of the presence of extraterrestrial bacterial life.