Suppressed competitive exclusion enabled the proliferation of Permian/Triassic boundary microbialites

Scientific paper - Original scientific paper

• Author: William J. Foster
• Author: Katrin Heindel
• Author: Sylvain Richoz
• Author: Jana Gliwa
• Author: Daniel J. Lehrmann
• Author: Aymon Baud
• Author: Tea Kolar‐Jurkovšek
• Author: Dunja Aljinović https://orcid.org/0000-0002-4698-1727
• Author: Bogdan Jurkovšek
• Author: Dieter Korn
• Author: Rowan C. Martindale
• Author: Jörn Peckmann
• Author's institution: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Mineralogy, Petrology and Mineral Resources)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology

Abstract (english)

During the earliest Triassic microbial mats flourished in the photic zones of marginal
seas, generating widespread microbialites. It has been suggested that anoxic
conditions in shallow marine environments, linked to the end-Permian mass extinction,
limited mat-inhibiting metazoans allowing for this microbialite expansion.
The presence of a diverse suite of proxies indicating oxygenated shallow sea-water
conditions (metazoan fossils, biomarkers and redox proxies) from microbialite successions
have, however, challenged the inference of anoxic conditions. Here, the
distribution and faunal composition of Griesbachian microbialites from China, Iran,
Turkey, Armenia, Slovenia and Hungary are investigated to determine the factors
that allowed microbialite-forming microbial mats to flourish following the end-
Permian crisis. The results presented here show that Neotethyan microbial buildups
record a unique faunal association due to the presence of keratose sponges, while the
Palaeotethyan buildups have a higher proportion of molluscs and the foraminifera
Earlandia. The distribution of the faunal components within the microbial fabrics
suggests that, except for the keratose sponges and some microconchids, most of the
metazoans were transported into the microbial framework via wave currents. The presence of both microbialites and metazoan associations were limited to oxygenated
settings, suggesting that a factor other than anoxia resulted in a relaxation of ecological
constraints following the mass extinction event. It is inferred that the end-Permian
mass extinction event decreased the diversity and abundance of metazoans to the
point of significantly reducing competition, allowing photosynthesis-based microbial
mats to flourish in shallow water settings and resulting in the formation of widespread
microbialites.

• Keywords (english): competitive exclusion; Permian/Triassic; mass extinction; microbialites; palaeoecology
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: The Depositional Record
• Numbering: vol. 6, no. 1, pp. 62-74
• p-ISSN: 2055-4877
• e-ISSN: 2055-4877
• DOI: https://doi.org/10.1002/dep2.97
• URN:NBN: urn:nbn:hr:169:939348
• Publication: 2020
• Online first: 2019-10-24
• Document URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/dep2.97
• Type of resource: Text
• Access conditions: Open access
• Created on: 2021-03-22 09:36:08