Soil erosion and fire contributed to Triassic mass extinction

During the Triassic period, early dinosaurs evolved but it wasn’t until mass extinction ushered in the Jurassic did dinosaur diversity explode. New research looks at the complex causes of the mass extinction event that paved the way for more dinosaurs. 

“This new study adds soil erosion and wildfire activity to the list of factors that drove this mass extinction to end the Triassic era, building on our previous research that found a rise in levels of acid and hydrogen sulfide in the ocean caused by rapid increases in carbon dioxide due to a surge in volcanic activity,” explained Dr. Calum Peter Fox of WA-Organic and Isotope Geochemistry Centre (WA-OIGC).

“Similar to modern large-scale fire events that are driven by climate change, periods of wildfire activity have significant impacts for land-dwelling fauna and flora and drive environmental and ecosystem stress that can lead to mass extinctions.”

Dr. Fox and colleagues investigated the ancient fires at the end of the Triassic and found similarities to the modern rise of atmospheric carbon. 

“By studying polycyclic aromatic hydrocarbons, which can be formed during the incomplete combustion of organic matter, we found that soil erosion was a more prominent terrestrial ecological stress than intensive wildfire activity during the end-Triassic mass extinction event in the Bristol Channel of the south-west United Kingdom,” said Dr. Fox.

“This tells us land and marine ecosystem and environmental stresses occurred at the same time and were likely exacerbated by soil erosion, with fire activity likely to be more localised in other areas rather than widespread across Europe.”

Professor Kliti Grice also found similarities between the modern land degradation caused by soil erosion and the likelihood of the same thing happening at the close of the Triassic. 

“These processes certainly have implications in the modern day due to the introduction of pollutants and pesticides,” said Professor Grice.

“Observing that soil erosion had major impacts in our history and in comparing and contrasting a global record of the past, we can anticipate the scale and duration of currently-occurring and future soil erosion events.”

The scientists hope that by looking to the past at previous mass extinction events, we might be able to better understand the one we’re living through now and potentially even mitigate it. 

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By Zach Fitzner, Earth.com Staff Writer