Asteroid impact, not volcanism, caused the end-Cretaceous dinosaur extinction

1,2Alfio Alessandro Chiarenza,3Alexander Farnsworth,2Philip D. Mannion,3Daniel J. Lunt,3Paul J. Valdes,1Joanna V. Morgan,1Peter A. Allison
Proceedings of the National Academy of Sciences of the United States of America 117, 17084-17093 Link to Article [DOI: https://doi.org/10.1073/pnas.2006087117]
1Department of Earth Science and Engineering, Imperial College London, South Kensington, SW7 2AZ London, United Kingdom;
2Department of Earth Sciences, University College London, WC1E 6BT London, United Kingdom;
3School of Geographical Sciences, University of Bristol, BS8 1TH Bristol, United Kingdom

The Cretaceous/Paleogene mass extinction, 66 Ma, included the demise of non-avian dinosaurs. Intense debate has focused on the relative roles of Deccan volcanism and the Chicxulub asteroid impact as kill mechanisms for this event. Here, we combine fossil-occurrence data with paleoclimate and habitat suitability models to evaluate dinosaur habitability in the wake of various asteroid impact and Deccan volcanism scenarios. Asteroid impact models generate a prolonged cold winter that suppresses potential global dinosaur habitats. Conversely, long-term forcing from Deccan volcanism (carbon dioxide [CO2]-induced warming) leads to increased habitat suitability. Short-term (aerosol cooling) volcanism still allows equatorial habitability. These results support the asteroid impact as the main driver of the non-avian dinosaur extinction. By contrast, induced warming from volcanism mitigated the most extreme effects of asteroid impact, potentially reducing the extinction severity.

 

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