A diverse Ediacara assemblage survived under low-oxygen conditions.

Autor: Cherry LB; Department of Atmospheric, Oceanic, and Earth Sciences, George Mason University, Fairfax, VA, USA. lucasbcherry1@gmail.com.; Department of Geology, University of Maryland, College Park, MD, USA. lucasbcherry1@gmail.com., Gilleaudeau GJ; Department of Atmospheric, Oceanic, and Earth Sciences, George Mason University, Fairfax, VA, USA. ggilleau@gmu.edu., Grazhdankin DV; Trofimuk Institute of Petroleum Geology and Geophysics, Russian Academy of Sciences, Siberian Branch, Novosibirsk, Russia., Romaniello SJ; School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA., Martin AJ; Division de Geociencias Aplicadas, IPICYT, CP 78216, San Luis Potosí, San Luis Potosí, Mexico., Kaufman AJ; Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2022 Nov 27; Vol. 13 (1), pp. 7306. Date of Electronic Publication: 2022 Nov 27.
DOI: 10.1038/s41467-022-35012-y
Abstrakt: The Ediacaran biota were soft-bodied organisms, many with enigmatic phylogenetic placement and ecology, living in marine environments between 574 and 539 million years ago. Some studies hypothesize a metazoan affinity and aerobic metabolism for these taxa, whereas others propose a fundamentally separate taxonomic grouping and a reliance on chemoautotrophy. To distinguish between these hypotheses and test the redox-sensitivity of Ediacaran organisms, here we present a high-resolution local and global redox dataset from carbonates that contain in situ Ediacaran fossils from Siberia. Cerium anomalies are consistently >1, indicating that local environments, where a diverse Ediacaran assemblage is preserved in situ as nodules and carbonaceous compressions, were pervasively anoxic. Additionally, δ 238 U values match other terminal Ediacaran sections, indicating widespread marine euxinia. These data suggest that some Ediacaran biotas were tolerant of at least intermittent anoxia, and thus had the capacity for a facultatively anaerobic lifestyle. Alternatively, these soft-bodied Ediacara organisms may have colonized the seafloor during brief oxygenation events not recorded by redox proxy data. Broad temporal correlations between carbon, sulfur, and uranium isotopes further highlight the dynamic redox landscape of Ediacaran-Cambrian evolutionary events.
(© 2022. The Author(s).)
Databáze: MEDLINE
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