At the Triassic-Jurassic boundary, 200 million years ago, some 60 percent of species living on Earth disappeared. Scientists suspected that magmatic activity and the release of CO2 were responsible for this environmental disaster. To corroborate this, one would need to find and to precisely date traces of this activity and make sure that it coincides with this mass extinction. The precise determination of this timing has been achieved by scientists at the University of Geneva, and is published in Nature Communications.