Extinction (optical mineralogy)

Ecosystem

Geology

Paleontology

Political science

Ecology

Earth science

Disturbance (geology)

Excursion

Coevolution

Carbon cycle

Biogeochemical cycle

Biology

Proceedings of the National Academy of Sciences

Significance Our understanding of the interactions between animal evolution, biogeochemical cycling, and global tectonics during the Ediacaran Period (635 to 541 Ma) is severely hampered by lack of a robust temporal framework. The appearance and extinction of the earliest fossil animals are hypothesized to correlate with upheavals in biogeochemical cycles—foremost the Shuram carbon isotope excursion, possibly the largest known disturbance to the global carbon cycle. However, without age constraints on the excursion’s timing and duration, its driving mechanisms, global synchroneity, and role in Ediacaran geobiological evolution cannot be evaluated. We provide radioisotopic ages for the onset and termination of the Shuram, evaluate its global synchroneity, and show that it is divorced from the rise of the earliest preserved animal ecosystems.

Calibrating the coevolution of Ediacaran life and environment