Scientists have discovered a plant refuge in northeastern China that survived the end-Permian mass extinction, which killed an estimated 80% of life on Earth 250 million years ago. The finding suggests that plants might have weathered the planet’s worst die-off, with seed-producing gymnosperm forests continuing to grow and spore-producing ferns thriving.
The discovery was made in rock layers from Xinjiang, China, which date back to the mass extinction event. Researchers found fossilized zircons containing radioactive elements, such as lead and uranium, that enabled them to determine the age of the rocks. The fossils also revealed a slow changeover of species, rather than a dramatic die-off and repopulation.
According to paleobotanist Josefina Bodnar, land plants have adaptations that allow them to survive mass extinctions. These include subterranean structures, roots, or stems that can persist for hundreds of years, and seeds that can remain dormant for long periods.
The plant refuge in Xinjiang was likely located in humid, high-latitude regions with lakes and rivers. The climate became drier during this period, but not enough to cause deforestation. This finding adds weight to the idea that the end-Permian mass extinction was more complicated on land than in the seas.
The discovery has implications for our understanding of past extinctions and their potential impact on human societies. It also highlights the importance of studying ancient catastrophes to learn from the planet’s memory.
Source: https://www.livescience.com/planet-earth/fossils