A Bayesian astrochronology for the Cambrian first occurrence of trilobites in West Gondwana (Morocco)

Sinnesael, Matthias; Millard, Andrew R; Smith, Martin R

Abstract

The first occurrence of trilobites ~520 million years ago is an iconic feature of the Cambrian Explosion. Developing a robust evolutionary view on early Cambrian life is generally hindered by large uncertainties in the ages of fossil finds, and their global stratigraphic correlation. Here, we develop an astrochronological interpretation for the Tiout section in Morocco that features some of the oldest trilobite fossils. Our novel approach to incorporating individual astronomical cycle durations in an integrated radio-isotopic and astrochronological Bayesian age-depth model results in an age estimate of 519.62 Ma (519.70-519.54 Ma 95% highest posterior distribution) for the first occurrence of trilobites in West Gondwana. This level of precise age estimation is exceptional for biological events in deep time and demonstrates the power of our novel approach.

Citation

Sinnesael, M., Millard, A. R., & Smith, M. R. (2024). A Bayesian astrochronology for the Cambrian first occurrence of trilobites in West Gondwana (Morocco). Geology, 52(3), 205-209. https://doi.org/10.1130/G51718.1

• Journal Article Type: Article
• Acceptance Date: Dec 18, 2023
• Online Publication Date: Jan 8, 2024
• Publication Date: Mar 1, 2024
• Deposit Date: Dec 12, 2023
• Publicly Available Date: Jan 9, 2024
• Journal: Geology
• Print ISSN: 0091-7613
• Electronic ISSN: 1943-2682
• Publisher: Geological Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 52
• Issue: 3
• Pages: 205-209
• DOI: https://doi.org/10.1130/G51718.1
• Public URL: https://durham-repository.worktribe.com/output/2023000