The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Mats Eriksson

Mats Eriksson

Professor

Mats Eriksson

First record of Cyanobacteria in Cambrian Orsten deposits of Sweden

Author

  • Christopher Castellani
  • Andreas Maas
  • Mats E. Eriksson
  • Joachim T. Haug
  • Carolin Haug
  • Dieter Waloszek

Summary, in English

The Swedish Cambrian ‘Orsten’-type fossil sites have yielded diverse secondarily phosphatized three-dimensionally preserved microfossils, mainly of arthropod affinities. Similar material has also been recorded from Canada, the UK, Poland, Siberia, China and Australia. Only one other non-arthropod group, the Cycloneuralia, is commonly reported from any of these sites, leading to the general assumption that ‘Orsten’-type preservation is largely restricted to animals with a chitin-containing cuticle. We describe here secondarily phosphatized, originally unmineralized, thread-shaped fossils etched out of Cambrian ‘Orsten’-type deposits from the Agnostus pisiformis Biozone of the Alum Shale Formation in Sweden. These fossils strikingly resemble specimens previously described from Precambrian deposits, with at least two different morphotaxa identified (Siphonophycus kestron Schopf and Oscillatoriopsis longa Timofeev & Hermann) as well as the modern Oscillatoria. This leads us to interpret the new fossils as unbranched, uniseriate filamentous cyanobacteria. Our morphological investigations, combined with morphometrics, allow grouping the specimens assigned to O. longa into two size classes, suggesting an even higher diversity within the ‘Orsten’ assemblages. The lack of cyanobacterial material in any sample younger than the A. pisiformis Biozone indicates that rather drastic changes occurred in the environment, that is, substrate conditions on the Alum Shale seafloor. This coincided with a significant change in the composition of the trilobite communities and onset of the globally recognized Steptoean Positive Isotope Carbon Excursion (SPICE) in Scandinavia.

Department/s

  • Lithosphere and Biosphere Science

Publishing year

2018

Language

English

Pages

855-880

Publication/Series

Palaeontology

Volume

61

Issue

6

Document type

Journal article

Publisher

Wiley-Blackwell

Topic

  • Geology

Keywords

  • Alum Shale Formation
  • Cambrian
  • exceptional preservation
  • filamentous cyanobacteria
  • Orsten
  • Oscillatoriopsis
  • Siphonophycus

Status

Published

ISBN/ISSN/Other

  • ISSN: 0031-0239