
Paleoart reconstruction depicting the Chicxulub impact event 66 million years ago and a post-impact cold, barren, and cloudy land-scape where the transition between the ‘Age of the Dinosaurs’ to the ‘Age of the Mammals’ is illustrated - surviving ground-dwelling mammaliaformes are present next to skeletons of the extinct Triceratops horridus and Dakotaraptor steini. Artwork by Aleksei Rodushkin.
16 January 2025
Sulphur less crucial to the demise of the dinosaurs
Sulphur in the atmosphere played a less important role in the extinction of dinosaurs than previously estimated, according to a new study published in Nature Communications. Researchers have found that the amount of sulphur in the atmosphere after the asteroid impact was five times less than previously thought. This likely meant a less drastic cooling of the climate, which may explain why mammals survived.
About 66 million years ago, an asteroid 10-15 kilometers wide hit the Yucatan Peninsula near the city of Chicxulub in modern-day Mexico. The impact was catastrophic for the plants and animals of the time. Large amounts of dust, soot and sulphur were released into the atmosphere, causing global cold and darkness for several years. 75% of the Earth's species became extinct and the event marked the end of the age of the dinosaurs.
Sulphur released into the atmosphere result in lower temperatures. A drastic global temperature drop related to release of large amounts of sulphur has long been seen as the main cause of the dinosaurs' death, until now.
“To understand how much the temperature dropped and how long it took for the climate to recover, we need to have a reliable value of the total amount of sulphur released during the impact,” says Katerina Rodiouchkina, Postdoctoral researcher in Applied Geochemistry at Luleå University of Technology and the scientific articles lead author.
The study is an international collaboration between Swedish, Belgian and German researchers. Katerina Rodiouchkina conducted the research during her time as a PhD student at Ghent University and Vrije Universiteit Brussel in Belgium and is now a researcher at Luleå University of Technology.
New way to estimate the amount of sulphur
Previous estimations of the sulphur amount has been calculated using simulations of the impact and assumptions of the sulphur content of the soil where the asteroid hit, resulting in widely varying results. Now, scientists have used a new way to estimate the amount of sulphur in the atmosphere after the impact.
“Instead of just focusing on the impact itself, we chose to look at what happened afterwards. The sulphur that was released from the impact site into the atmosphere was spread around the world. It eventually fell back to the Earth's surface for months or even years after the impact. We identified and analysed this sulphur in sediments at several sites around the globe to estimate the total amount of sulphur that entered the atmosphere after the asteroid impact,’ says Katerina Rodiouchkina.
Five times less
The new study shows that the amount of sulphur in the atmosphere after the impact was about five times lower than previously estimated. Dust and soot in the atmosphere have less of a temperature impact than sulphur, but other recent studies have shown that they have a major impact on the influx of light and thus on all vegetation on Earth. Five times less sulphur in the atmosphere than previously estimated suggests that it was the lack of light that led to the mass extinction rather than temperature.
”For a very long time, the drop in temperature was seen as the main cause of the extinction of the dinosaurs. But our results suggest that Earth was probably not as cold as previous climate studies have shown. This also makes more sense in relation to the fact that many species still survived, which gave mammals the chance to evolve and eventually leading to us humans existing today,” says Katerina Rodiouchkina.
Read more
- Reduced contribution of sulfur to the mass extinction associated with the Chicxulub impact event
External link.
The article is published in Nature Communications

Katerina Rodiouchkina
Contact
Katerina Rodiouchkina
- Postdoctoral researcher
- 0920-492852
- katerina.rodiouchkina@ltu.se
- Katerina Rodiouchkina
Published:
Updated: