Laser–Raman imagery of Earth's earliest fossils

  title={Laser–Raman imagery of Earth's earliest fossils},
  author={J. William Schopf and Anatoliy B. Kudryavtsev and David G. Agresti and Thomas John Wdowiak and Andrew D. Czaja},
Unlike the familiar Phanerozoic history of life, evolution during the earlier and much longer Precambrian segment of geological time centred on prokaryotic microbes. Because such microorganisms are minute, are preserved incompletely in geological materials, and have simple morphologies that can be mimicked by nonbiological mineral microstructures, discriminating between true microbial fossils and microscopic pseudofossil ‘lookalikes’ can be difficult. Thus, valid identification of fossil… 
Distinguishing biology from geology in soft-tissue preservation.
Knowledge of evolutionary history is based extensively on relatively rare fossils that preserve soft tissues. These fossils record a much greater proportion of anatomy than would be known solely from
A fresh look at the fossil evidence for early Archaean cellular life
The rock record provides unique evidence for testing models as to when and where cellular life first appeared on Earth, but its study, however, requires caution and critical analysis of morphospace and context is needed.
Hot spring sinters: keys to understanding Earth's earliest life forms
The question of what composed the Earth's oldest fossils is the subject of current debate. At present, taphonomical determination of Archean silicified microfossils is largely based on morphological
Revealing the biotic origin of silicified Precambrian carbonaceous microstructures using Raman spectroscopic mapping, a potential method for the detection of microfossils on Mars
Demonstrating the biogenicity of carbonaceous microfossils can be relatively difficult because of their small size and simple shape, and to the degradation of the associated organic molecules with
Morphological preservation of carbonaceous plant fossils in blueschist metamorphic rocks from New Zealand
This occurrence demonstrates that plant macrofossils may experience major geodynamic processes such as metamorphism and exhumation involving deep changes and homogenization of their carbon chemistry and structure but still retain their morphology with remarkable integrity even if they are not shielded by any hard-mineralized concretion.
SIMS analyses of the oldest known assemblage of microfossils document their taxon-correlated carbon isotope compositions
Significance Although the existence of the Archaea (one of three all-encompassing domains of life) in the Archean Eon (4,000 to 2,500 million years ago) has been inferred from carbon isotopes in bulk
Three-Dimensional Morphological (CLSM) and Chemical (Raman) Imagery of Cellularly Mineralized Fossils
Of all modes of fossilization, cellular mineralization, whether by the ­non-biologic process of permineralization (“petrifaction”) or by microbially ­mediated mineral precipitation (“authigenic
Geomicrobiological study of modern microbialites from Mexico: towards a better understanding of the ancient fossil record
It is shown that very diverse microbial communities populate these microbialites, including diverse microbial groups able to induce carbonate precipitation, and a new deep- branching cyanobacterium species, Candidatus Gloeomargarita lithophora, able to form intracellular Ca-, Mg-, Sr- and Ba-rich carbonates is found.


In situ laser-Raman imagery of precambrian microscopic fossils.
Laser-Raman imagery is a sensitive, noninvasive, and nondestructive technique that can be used to correlate directly chemical composition with optically discernable morphology in ancient carbonaceous
Filamentous microfossils from the 3,500-Myr-old Onverwacht Group, Barberton Mountain Land, South Africa
The Swaziland Supergroup, Barberton Mountain Land, South Africa, has long been regarded as a promising location for the Earth's oldest fossils because it includes some of the most ancient
Late Precambrian Microfossils: a New Stromatolitic Biota from Boorthanna, South Australia
OF the four dozen fossiliferous Precambrian sediments now known1, only a very few contain diverse microfossil assemblages preserved in situ on which inferences of ecologic setting and evolutionary
The Proterozoic biosphere : a multidisciplinary study
List of contributors Preface Part I: 1. Geology and paleobiology of the Archean Earth 2. Geological evolution of the Proterozoic Earth 3. Proterozoic biochemistry 4. Proterozoic atmosphere and ocean
Carbon isotopic composition of individual Precambrian microfossils.
The isotopic results are not consistent with the degree of fractionation expected from either the 3-hydroxypropionate cycle or the reductive tricarboxylic acid cycle, suggesting that the microfossils studied did not use either of these pathways for carbon fixation.
Microfossils of the Early Archean Apex Chert: New Evidence of the Antiquity of Life
It is established that trichomic cyanobacterium-like microorganisms were extant and morphologically diverse at least as early as ∼3465 million years ago and suggests that oxygen-producing photoautotrophy may have already evolved by this early stage in biotic history.
Early Archean (3.3-billion to 3.5-billion-year-old) microfossils from Warrawoona Group, Australia.
Cellularly preserved filamentous and colonial fossil microorganisms have been discovered in bedded carbonaceous cherts from the Early Archean Apex Basalt and Towers Formation of northwestern Western
Evidence for a higher pH in the glacial ocean from boron isotopes in foraminifera
RECORDS of past changes in the pH of the oceans should provide insights into how the carbonate chemistry of the oceans has changed over time. The latter is related to changes in the atmospheric CO2