Rapid marine oxygen variability: Driver of the Late Ordovician mass extinction

Kozik, Nevin P.; Young, Seth A.; Newby, Sean M.; Liu, Mu; Chen, Daizhao; Hammarlund, Emma; Bond, David P.G.; Them, Theodore R.; Owens, Jeremy D.

Abstract

The timing and connections between global cooling, marine redox conditions, and biotic turnover are underconstrained for the Late Ordovician. The second most severe mass extinction occurred at the end of the Ordovician period, resulting in ~85% loss of marine species between two extinction pulses. As the only "Big 5" extinction that occurred during icehouse conditions, this interval is an important modern analog to constrain environmental feedbacks. We present a previously unexplored thallium isotope records from two paleobasins that record global marine redox conditions and document two distinct and rapid excursions suggesting vacillating (de)oxygenation. The strong temporal link between these perturbations and extinctions highlights the possibility that dynamic marine oxygen fluctuations, rather than persistent, stable global anoxia, played a major role in driving the extinction. This evidence for rapid oxygen changes leading to mass extinction has important implications for modern deoxygenation and biodiversity declines.

Citation

Kozik, N. P., Young, S. A., Newby, S. M., Liu, M., Chen, D., Hammarlund, E., …Owens, J. D. (2022). Rapid marine oxygen variability: Driver of the Late Ordovician mass extinction. Science Advances, 8(46), eabn8345. https://doi.org/10.1126/sciadv.abn8345

• Journal Article Type: Article
• Acceptance Date: Sep 30, 2022
• Online Publication Date: Nov 18, 2022
• Publication Date: Nov 16, 2022
• Deposit Date: Oct 12, 2022
• Publicly Available Date: Nov 21, 2022
• Journal: Science advances
• Electronic ISSN: 2375-2548
• Publisher: American Association for the Advancement of Science
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 46
• Pages: eabn8345
• DOI: https://doi.org/10.1126/sciadv.abn8345
• Public URL: https://hull-repository.worktribe.com/output/4094081