Extensive marine anoxia during the terminal Ediacaran Period.

Abstract in brief

• The study investigates the decline of the Ediacara biota during the terminal Ediacaran Period by analyzing uranium isotope compositions in sedimentary carbonates from South China, revealing the most negative values reported, which indicate extensive oceanic anoxia.
• The findings suggest that during this time, nearly 21% of the seafloor was covered by anoxic conditions, with significant removal of uranium into sediments, pointing to a major expansion of anoxia in the global oceans.
• The research proposes that such widespread and episodic oceanic anoxia may have played a key role in the decline of the Ediacara biota and could have even encouraged the development of animal motility by creating diverse redox environments.