Transient metazoan reefs in the aftermath of the end-Permian mass extinction.

• Published in: Nature Geoscience
• Main Authors: Brayard, Arnaud, Vennin, Emmanuelle, Olivier, Nicolas, Bylund, Kevin G., Jenks, Jim, Stephen, Daniel A., Bucher, Hugo, Hofmann, Richard, Goudemand, Nicolas, Escarguel, Gilles
• Other Authors: Biogéosciences UMR 6282 Dijon (BGS), Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement Lyon (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Department of Earth Science, Utah Valley University (UVU), Paläontologisches Institut und Museum, Universität Zürich Zürich (UZH), Work funded by the Région Bourgogne, the FRB, the INSU Interrvie, and by the Swiss NSF project 200020-113554.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy; Ocean acidification
• Online Access: https://hal.archives-ouvertes.fr/hal-00628213; https://doi.org/10.1038/NGEO1264

5 pages International audience Recovery from the devastating Permian-Triassic mass extinction about 252 million years ago is usually assumed to have spanned the entire 5 million years of the Early Triassic epoch1,2. The post-crisis interval was characterized by large-scale fluctuations of the global carbon cycle and harsh marine conditions, including a combination of ocean acidification, euxinia, and fluctuating productivity3. During this interval, metazoan-dominated reefs are thought to have been replaced by microbial deposits that are considered the hallmark of the Early Triassic4-7. Here we use field and microscopic investigations to document Early Triassic bioaccumulations and reefs from the western USA that comprise of various sponges and serpulids associated with microbialites and other eukaryotic benthic organisms. These metazoan-rich reefs were formed only 1.5 million years after the extinction, in contrast to previous suggestions of a much delayed recovery of complex benthic communities. We conclude that the predominance of microbial reefs following the mass extinction is restricted to short intervals of the earliest Triassic. We suggest that metazoan reef building continued throughout the Early Triassic wherever permitted by environmental conditions.