Skip to main content Accessibility help
×
Home

Shape analysis of filamentous Precambrian microfossils and modern cyanobacteria

  • David Boal (a1) and Ray Ng (a1)

Abstract

Variations in the orientation and cross-sectional shape of filamentous microfossils provide quantitative measures for characterizing them and probing their native mechanical structure. Here, we determine the tangent correlation length, which is the characteristic length scale for the variation in direction of a sinuous curve, for both a suite of Precambrian filamentous microfossils and six strains of modern filamentous cyanobacteria, all with diameters of a few microns. Among 1.9-2-Ga microfossils, Gunflintia grandis, Gunflintia minuta and Eomycetopsis filiformis possess, respectively, correlation lengths of 360 ± 40 μm, 670 ± 40 μm and 700 ±100 μm in two dimensions. Hundreds of times larger than the filament diameters, these values lie in the same range as the cyanobacteria Geitlerinema and Pseudanabaena, but are smaller than several strains of Oscillatoria. In contrast, the 2-Ga microfossil trichome Halythrix, is found to have a short correlation length of 29 ± 4 μm in two dimensions. Micron-wide pyritic replacement filaments observed in 3.23-Ga volcanogenic deposits also display a modest correlation length of 100 ± 15 μm in two dimensions. Sequences of species in two genera of our modern cyanobacteria possess tangent correlation lengths that rise as a power of the filament diameter DD 3.3 ± 1 for Oscillatoria and D 5.1 ± 1 for Geitlerinema. These results can be compared with power-law scaling of D3 for hollow tubes and D4 for solid cylinders that is expected from continuum mechanics. Extrapolating the observed scaling behavior to smaller filament diameters, the measured correlation length of the pyrite filaments is consistent with modern Geitlerinema whereas that of Halythrix lies not far from modern Oscillatoria, suggesting that there may be structural similarities among these genera.

Copyright

References

Hide All
Atlas, R. M. 2004. Handbook of microbiological media. CRC Press, Boca Raton, Fla.
Awramik, S. M., and Barghoorn, E. S. 1977. Gunflint microbiota. Precambrian Research 5:121142.
Barghoorn, E. S., and Schopf, J. W. 1966. Microorganisms three billion years old from the Precambrian of South Africa. Science 152:758763.
Barghoorn, E. S., and Tyler, S. A. 1965. Microorganisms from the Gunflint chert. Science 147:563577.
Boal, D. H. 2002. Mechanics of the cell. Cambridge University Press, Cambridge.
Brasier, M. D., Green, O. R., Jephcoat, A. P., Kleppe, A. K., Van Kranendonk, M. J., Lindsay, J. F., Steele, A., and Grassineau, N. V. 2002. Questioning the evidence for Earth's oldest fossils. Nature 416:7681.
Buick, R., Brauhart, C. W., Morant, P., Thornett, J. R., Maniw, J. G., Archibald, N. J., Doepel, M. G., Fletcher, I. R., Pickard, A. L., Smith, J. B., Barley, M. E., McNaughton, N. J., and Groves, D. I. 2002. Geochronology and stratigraphic relationships of the Sulphur Springs Group and Strelley Granite: a temporally distinct igneous province in the Archaean Pilbara Craton, Australia. Precambrian Research 114:87120.
Cloud, P. E. Jr. 1965. Significance of the Gunflint (Precambrian) microflora. Science 148:2735.
Fralick, P., Davis, D. W., and Kissin, S. A. 2002. The age of the Gunflint Formation, Ontario, Canada: single zircon U-Pb age determinations from reworked volcanic ash. Canadian Journal of Earth Sciences 39:10851091.
Furnes, H., Banerjee, N. R., Muehlenbachs, K., Staudigel, H., and de Wit, M. 2004. Early life recorded in Archean pillow lavas. Science 304:578581.
Golubic, S., and Hofmann, H. J. 1976. Comparison of modern and mid-Precambrian Entophysalidaceae (Cyanophyta) in stromatolitic algal mats: cell division and degradation. Journal of Paleontology 50:10741082.
Hofmann, H. J. 1975. Stratiform, Precambrian stromatolites, Belcher Islands, Canada: relations between silicified microfossils and microstructure. American Journal of Science 275:11211132.
Hofmann, H. J. 1976. Precambrian microflora, Belcher Islands, Canada: significance and systematics. Journal of Paleontology 50:10401073.
Knoll, A. H., and Barghoorn, E. S. 1974. Ambient pyrite in Precambrian chert: new evidence and a theory. Proceedings of the National Academy of Sciences USA 71:23292331.
Knoll, A. H., Barghoorn, E. S., and Awramik, S. M. 1978. New microorganisms from the Aphebian Gunflint Iron Formation, Ontario. Journal of Paleontology 52:976992.
Rasmussen, B. 2000. Filamentous microfossils in a 3.235-million-year-old volcanogenic massive sulphide deposit. Nature 405:676679.
Rippka, R. 1988. Isolation and purification of cyanobacteria. Methods in Enzymology 167:327.
Schopf, J. W. 1968. Microflora of the Bitter Springs Formation, Late Precambrian, central Australia. Journal of Paleontology 42:651688.
Schopf, J. W. 1993. Microfossils of the Early Archean Apex chert: new evidence of the antiquity of life. Science 260:640646.
Schopf, J. W., and Packer, B. M. 1987. Early Archean (3.3-billion to 3.5 billion-year-old) microfossils from Warrawoona Group, Australia. Science 237:7073.
Tyler, S. A., and Barghoorn, E. S. 1963. Ambient pyrite grains in Precambrian cherts. American Journal of Science 261:424432.
Vearncombe, S., Barley, M. E., Groves, D. I., McNaughton, N. J., Mikucki, E. J., and Vearncombe, J. R. 1995. 3.26 Ga black smoker-type mineralization in the Strelley Belt, Pilbara Craton, Western Australia. Journal of the Geological Society, London 152:587590.
Walsh, M. M., and Lowe, D. R. 1985. Filamentous microfossils from the 3,500Myr-old Onverwacht Group, Barberton Mountain Land, South Africa. Nature 314:530532.

Shape analysis of filamentous Precambrian microfossils and modern cyanobacteria

  • David Boal (a1) and Ray Ng (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed