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Fossil actinomycetes and other bacteria have been found in sulfide minerals from "varved" argillites in the middle Precambrian Cobalt Series of Canada. The fossils consist of branched and unbranched nonseptate hyphae and chains of rod-shaped cells. The presence of actinomycetes is consistent with the theory that the argillites are lacustrine desposits.
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Togwell A. Jackson (1967) studied this question.
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