A Chronostratigraphic Framework for the Rise of the Ediacaran Macrobiota: New Constraints from Mistaken Point Ecological Reserve, Newfoundland

New radioisotopic dating of volcanic tuffites at the Mistaken Point Ecological Reserve, Newfoundland, provides precise age constraints for the rise and diversification of Ediacaran macrobiota, some of the earliest known animal fossils. The study reveals that architecturally complex fossils date back to 574.17 ± 0.66 million years ago (Ma), while rangeomorphs from the Fermeuse Formation are confirmed to be no younger than 564.13 ± 0.65 Ma. Exceptionally preserved specimens on the 'Brasier' Surface in the Briscal Formation are dated at 567.63 ± 0.66 Ma, and fossils from the famous 'E' Surface are confirmed to be 565.00 ± 0.64 Ma. This age-depth model enables the conversion of stratigraphic fossil ranges into a time-calibrated framework, facilitating the study of evolutionary signals during the mid-late Ediacaran Period. The research highlights peak taxonomic diversity within the Mistaken Point and Trepassey Formations and shows that uniterminal rangeomorphs with undisplayed branching architecture appeared several million years before multiterminal, displayed forms.

Matthews, J. J., Liu, A. G., Yang, C., McIlroy, D., Levell, B., & Condon, D. J. (2020). A Chronostratigraphic Framework for the Rise of the Ediacaran Macrobiota: New Constraints from Mistaken Point Ecological Reserve, Newfoundland. GSA Bulletin, 133(3-4), 612–624. https://doi.org/10.1130/b35646.1