Extinction intensity during Ordovician and Cenozoic glaciations explained by cooling and palaeogeography

Journal article

A striking feature of the marine fossil record is the variable intensity of extinction during superficially similar climate transitions. Here we combine climate models and species trait simulations to explore the degree to which differing paleogeographic boundary conditions and differing magnitudes of cooling and glaciation can explain the relative intensity of marine extinction during greenhouse-icehouse transitions in the Late Ordovician and the Cenozoic. Simulations modelled the response of virtual species to cooling climate using a spatially explicit cellular automaton algorithm. We find that paleogeography alone may be a minor contributing factor, as identical changes in meridional sea surface temperature gradients caused greater extinction in Late Ordovician simulations than in Cenozoic simulations. Differences in extinction from paleogeography are significant but by themselves insufficient to explain observed differences in extinction intensity. However, when simulations included inferred changes in continental flooding and interval-specific models of sea surface temperature, predicted differences in relative extinction intensity were more consistent with observations from the fossil record. Our results support the hypothesis that intense extinction in the Late Ordovician is partially attributable to exceptionally rapid and severe cooling compared to Cenozoic events.

Authors: Saupe, E; Qiao, H; Donnadieu, Y; Farnsworth, A; Kennedy-Asser, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Nature Geoscience
• Volume: 13
• Issue: 2020
• Pages: 65-70
• Publication date: 2019-12-16
• Acceptance date: 2019-11-04
• DOI: 10.1038/s41561-019-0504-6
• EISSN: 1752-0908
• ISSN: 1752-0894
• Language: English
• Keywords: FFR