Searching for land refugia becomes imperative for human survival during the hypothetical sixth mass extinction. Studying past comparable crises can offer insights, but there is no fossil evidence of diverse megafloral ecosystems surviving the most severe biotic crisis in the past 540 million years — the end-Permian mass extinction. In new research, paleontologists investigated plant and tetrapod fossils and various microfossils from the Permian-Triassic South Taodonggou section in Xinjiang, China. Their fossil records reveal the presence of vibrant regional gymnospermous forests and fern fields, while marine organisms experienced mass extinction.
Artistic reconstruction of the terrestrial ecological landscape during, before, and after the end of the Permian mass extinction based on fossil palynomorphs, plants, and tetrapods recovered, as well as sedimentological data from the South Taodonggou section in Xinjiang, China. Image credit: D.H. Yang.
The end-Permian mass extinction, which occurred approximately 252 million years ago, is widely recognized as the most severe among the five major Phanerozoic extinctions.
This catastrophic event resulted in the extinction of approximately 80% of known species, a fact well-supported by marine fossil records.
Some scientists suggest that volcanic eruptions in Siberia triggered widespread terrestrial devastation through wildfires, acid rain, and toxic gases.
Evidence for this includes the successive extinction of characteristic Gigantopteris flora in South China and typical Glossopteris flora across Gondwanaland around the end-Permian mass extinction.
However, other scientists argue that these catastrophic effects were limited by latitude and atmospheric circulation.
Some fossil discoveries even suggest that certain Mesozoic plants existed before the extinction event, pointing to uninterrupted evolution.
The newly-discovered fossils from the South Taodonggou section, located in the Turpan-Hami Basin of Xinjiang province, northwestern China, offer a unique perspective.
“The presence of intact tree trunks and fern stems further confirms that these microfossils represent local vegetation, not transported remnants,” said Professor Mingli Wan, a researcher with the Nanjing Institute of Geology and Palaeontology at the Chinese Academy of Sciences.
Although some plant species disappeared locally, the researchers found that the overall extinction rate of spore and pollen species in the South Taodonggou section was possibly only about 21% — far lower than the marine extinction rate during the same period.
This conclusion was based on the discovery of many ‘missing’ species in Early Triassic layers elsewhere, indicating temporary migration rather than permanent extinction.
This stable vegetation base was crucial for the rapid recovery of the local ecosystem.
Fossil evidence shows that within just 75,000 years after the extinction ended, the area supported diverse tetrapods, including herbivorous Lystrosaurus and carnivorous chroniosuchians, demonstrating a quick return to a complex food web.
This discovery contrasts with the previous understanding that ecosystem recovery after the end-Permian extinction took over a million years.
The new evidence suggests local ecological diversity in this area recovered more than ten times faster than in other regions.
The scientists cited the region’s stable, semi-humid climate as crucial to its biological resilience. According to analysis of paleosol matrices, the region consistently received about 1,000 mm of rainfall per year during this time.
Due to its consistent precipitation, South Taodonggou offered more abundant vegetation and a more habitable environment than other regions following the end-Permian mass extinction, providing vital support for migrating animals.
Despite its proximity to the volcanic activity that triggered the end-Permian extinction, the Turpan-Hami Basin provided a safe haven for terrestrial life, demonstrating that even seemingly dangerous locations can harbor crucial biodiversity.
“This suggests that local climate and geographic factors can create surprising pockets of resilience, offering hope for conservation efforts in the face of global environmental change,” said Professor Feng Liu, also from the Nanjing Institute of Geology and Palaeontology at the Chinese Academy of Sciences.
“In light of current concerns about a potential sixth mass extinction driven by human activity, the discovery of this ‘Life Oasis’ highlights the importance of identifying and protecting such natural refugia.”
The study was published in the journal Science Advances.
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Huiping Peng et al. 2025. Refugium amidst ruins: Unearthing the lost flora that escaped the end-Permian mass extinction. Science Advances 11 (11); doi: 10.1126/sciadv.ads5614
