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Astronomically calibrating early Ediacaran evolution
Tan Zhang1,2,3, Chao Ma4,5, Yifan Li6
1State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation & Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, 610059, China.
Nature Communications
|March 29, 2025
Summary
A new astrochronological framework for the early Ediacaran Period reveals rapid deglaciation and global synchronicity of environmental events. This enhances understanding of early life evolution and ecosystem complexity.
Area of Science:
- Paleoclimatology
- Paleontology
- Geochronology
Background:
- Low-resolution chronostratigraphy of the early Ediacaran hinders understanding of environmental changes and evolutionary innovation.
- Establishing precise timelines is crucial for linking geological events to biological evolution.
Purpose of the Study:
- To establish a high-resolution astrochronological framework for the early Ediacaran Period.
- To precisely date key environmental and biotic events, including glaciations, carbon isotope excursions, and fossil assemblages.
- To refine the age model for early Ediacaran biotic evolution.
Main Methods:
- Astrochronology applied to key sections from South China.
- Integration with multiple radioisotopic dates to anchor the timescale.
- Correlation of dated events with global paleoclimatic and paleoenvironmental markers.
Main Results:
- A ~57.6-million-year high-resolution astrochronological framework for the early Ediacaran was established.
- The Marinoan deglaciation in South China was rapid (10^6-10^7 years).
- Global synchroneity of Marinoan deglaciation, Ediacaran Negative carbon isotope excursions 1 and 2 (EN1 and EN2), and key fossil assemblages was robustly demonstrated.
Conclusions:
- The refined chronology provides a precise age model for early Ediacaran biotic evolution.
- Ecosystems gradually increased in complexity over millions of years.
- Rapid transitions to novel communities coincided with biogeochemical perturbations, despite stable global taxonomic diversity.
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