The oldest fossils of Africa – a brief reappraisal of reports from the Archean

Abstract

From the Archean sedimentary rocks of Africa numerous reports of cellularly preserved microfossils were published since 1960. Until the first report of authentic microfossils from the Barberton Greenstone Belt [M.M. Walsh, D.R. Lowe, Nature 314 (1985) 530], however, none of these reports stood up to the criteria for confirming authenticity and originality of Archean microfossils. According to these criteria, only less than 10 microfossil reports from the Archean of Africa can be recognised as indeed cellularly preserved microbes. All of them are from Southern Africa, namely from the territory of the Republic of South Africa. Nevertheless, these few occurrences provide evidence for a very advanced evolutionary stage of Archean microbiota and are thus key contributions to our knowledge of the early life on Earth. They demonstrate the presence of coccoid and filamentous bacteria and cyanobacteria in the Archean and also confirm the development of aerobic and anaerobic photosynthesis and of biogenic calcium precipitation in the Archean. Therefore, the contribution of the African continent to the knowledge of Archean biology and the early evolution of life is of immense value to paleobiological science.