Calibrating the coevolution of Ediacaran life and environment
Name
16824.full.pdf
Description
Published version
Size
1.27 MB
Format
Adobe PDF
Checksum (MD5)
00b27597c0551aa5305ff8f35f5d3a07
Author(s)
Rooney, Alan D.
Cantine, Marjorie Dianne
Bergmann, Kristin
Gómez-Pérez, Irene
Al Baloushi, Badar
Boag, Thomas H.
Busch, James F.
Sperling, Erik A.
Strauss, Justin V.
Date Issued
July 2020
Journal
Proceedings of the National Academy of Sciences
Publisher
Proceedings of the National Academy of Sciences
Citation
Rooney, Alan D. et al. "Calibrating the coevolution of Ediacaran life and environment." Proceedings of the National Academy of Sciences 117, 29 (July 2020): 16824-16830. © 2020 National Academy of Sciences
Version
Final published version
Abstract
The rise of animals occurred during an interval of Earth history that witnessed dynamic marine redox conditions, potentially rapid plate motions, and uniquely large perturbations to global biogeochemical cycles. The largest of these perturbations, the Shuram carbon isotope excursion, has been invoked as a driving mechanism for Ediacaran environmental change, possibly linked with evolutionary innovation or extinction. However, there are a number of controversies surrounding the Shuram, including its timing, duration, and role in the concomitant biological and biogeochemical upheavals. Here we present radioisotopic dates bracketing the Shuram on two separate paleocontinents; our results are consistent with a global and synchronous event between 574.0 ± 4.7 and 567.3 ± 3.0 Ma. These dates support the interpretation that the Shuram is a primary and synchronous event postdating the Gaskiers glaciation. In addition, our Re-Os ages suggest that the appearance of Ediacaran macrofossils in northwestern Canada is identical, within uncertainty, to similar macrofossils from the Conception Group of Newfoundland, highlighting the coeval appearance of macroscopic metazoans across two paleocontinents. Our temporal framework for the terminal Proterozoic is a critical step for testing hypotheses related to extreme carbon isotope excursions and their role in the evolution of complex life.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
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DOI of Published Version
https://doi.org/10.1073/pnas.2002918117
