The search for microfossils in the geological record has been a long-term challenge. Part of the problem comes from the difficulty of identifying such microfossils unambiguously, since they can be morphologically confused with abiotic biomorphs. One route to improve our ability to correctly identify microfossils involves studying fossilization processes affecting bacteria in modern settings. We...

Sulphur isotope data from early Archaean rocks suggest that microbes with metabolisms based on sulphur existed almost 3.5 billion years ago, leading to suggestions that the earliest microbial ecosystems were sulphur-based1–5. However, morphological evidence for these sulphur-metabolizing bacteria has been elusive. Here we report the presence of microstructures from the 3.4-billion-year-old Stre...

Walter, M.R. and Awramik, S.M., 1979. Frutexites from stromatolites of the Gunflint Iron Formation of Canada, and its biological affinities. Precambrian Res., 9: 23--33. The microfossil Frutexites is known from many Palaeozoic and some Proterozoic carbonate sedimentary rocks. We recently found unusually well-preserved examples in the early Proterozoic Gunflint Iron Formation of Ontario, Canada....

Homochirality of the biomolecules (D-sugars of DNA and RNA and L-amino acids of proteins) is a fundamental property of all life on Earth. Abiotic mechanisms yield racemic mixtures (D/L=1) of chiral molecules and after the death of an organism, the enantiopure chiral biomolecules slowly racemize. Several independent investigators have now established that the amino acids present in CI1 and CM2 c...

logues rocks during entry into the Earth’s atmosphere F. Foucher, F. Westall , J.-M. Bény , F. Brandstätter , and R. Demets , 1 Centre de Biophysique Moléculaire, UPR CNRS 4301, Orléans, France ([email protected]), 2 Institut des Sciences de la Terre d’Orléans, UMR CNRS 6113, Orléans, France, 3 Naturhistorisches Museum, Burgring 7, 1010 Wien, Austria, 4 European Space & Technolog...

Accumulated records of organic microfossils span billions years Earth history. The majority this record consists prokaryotes plus eukaryotes a protistan grade, yet type fossilisation is also capable capturing the organically preserved remains animals. Recently, it has become apparent that non-biomineralizing animal groups, otherwise known only from rare instances exceptional fossilisation, can ...

Coupled dual-beam focused ion beam electron microscopy (FIB-EM) has gained popularity across multiple disciplines over the past decade. Widely utilized as a stand-alone instrument for micromachining and metal or insulator deposition in numerous industries, the submicron-scale ion milling and cutting capabilities of FIB-EM systems have been well documented in the materials science literature. Th...

Features for a new application in pattern recognition are presented. The objects to be classiied are coccoliths (marine microfos-sils). Since the objects diier both in their outline and in their internal structure the features developed take into consideration both kinds of variability. The features concerning the internal structure are computed on the grey-value images produced by a scanning e...