Fossilized giant sulfide-oxidizing bacteria from the Devonian Hollard Mound seep deposit, Morocco
- Author(s)
- Daniel Smrzka, Jennifer Zwicker, Heide Schulz-Vogt, Crispin T.S. Little, Max Rieder, Patrick Meister, Susanne Gier, Jörn Peckmann
- Abstract
The giant sulfide-oxidizing bacteria are particularly prone to preservation in the rock record, and their fossils have been identified in ancient phosphorites, cherts, and carbonates. This study reports putative spherical fossils preserved in the Devonian Hollard Mound hydrocarbon-seep deposit. Based on petrographical, mineralogical, and geochemical evidence the putative microfossils are interpreted as sulfide-oxidizing bacteria similar to the present-day genus Thiomargarita, which is also found at modern hydrocarbon seeps. The morphology, distribution, size, and occurrence of the fossilized cells show a large degree of similarity to their modern counterparts. Some of the spherical fossils adhere to worm tubes analogous to the occurrence of modern Thiomargarita on the tubes of seep-dwelling siboglinid worms. Fluorapatite crystals were identified within the fossilized cell walls, suggesting the intercellular storage of phosphorus analogous to modern Thiomargarita cells. The preservation of large sulfide-oxidizing bacteria was probably linked to changing biogeochemical processes at the Hollard Mound seep or, alternatively, may have been favored by the sulfide-oxidizing bacteria performing nitrate-dependent sulfide oxidation—a process known to induce carbonate precipitation. The presence of sulfide-oxidizing bacteria at a Devonian hydrocarbon seep highlights the similarities of past and present chemosynthesis-based ecosystems and provides valuable insight into the antiquity of biogeochemical processes and element cycling at Phanerozoic seeps.
- Organisation(s)
- Department of Mineralogy and Crystallography, Department of Geology
- External organisation(s)
- Universität Bremen, Leibniz-Institut für Ostseeforschung, University of Leeds, Natural History Museum London, Geologie Weixelberger GmbH, Universität Hamburg
- Journal
- Geobiology
- Volume
- 22
- ISSN
- 1472-4677
- DOI
- https://doi.org/10.1111/gbi.12581
- Publication date
- 2023
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105121 Sedimentology
- Keywords
- ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics, General Environmental Science, General Earth and Planetary Sciences
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/059d02af-2da1-466d-ad43-5e2e6b4231d0