The Permian–Triassic Mass Extinction (Great Dying)

The Permian–Triassic Mass Extinction (Great Dying)

Name of time / event: Permian–Triassic Mass Extinction (often called the “Great Dying”) When it happened: ~252 million years ago How long it lasted: The main extinction happened over tens to hundreds of thousands of years), Type of division: It’s an event/ boundary World

Earth had warm climate, but large volcanic provinces (Siberian Traps) started releasing massive amounts of heat and gases. Oceans became acidified, lost oxygen, and many areas became uninhabitable for marine life. On land, ecosystems were stressed by climate change, changes in precipitation, and habitat loss. Life was mostly marine; many species lived in seas, and terrestrial life (plants, insects, early reptiles) existed but were vulnerable.

Gomez Correa, M. A. (2024). Reconstructing end-Permian mass extinction conditions using the ostracod record. Nature Reviews Earth & Environment. Shen, J., Chen, J., Algeo, T., Yuan, S., & others. (2019). Evidence for a prolonged Permian–Triassic extinction interval from global marine mercury records. Nature Communications, 10, 1563.

Major Event & What Happened

This event wiped out ~90% of marine species and ~70% of terrestrial species , he largest extinction in Earth’s history. Caused massive volcanic activity in Siberia (Siberian Traps) released huge amounts of CO₂, causing global warming, ocean anoxia (lack of oxygen), ocean acidification, and disruptions to the carbon cycle. The extinction may have occurred in phases, not all at once

Interesting Facts

Mercury spikes in marine sediments suggest volcanic eruptions increased just before and during the extinction. Warming of ~10–12 °C is estimated in ocean and surface temperatures during the event. Some marine organisms survived in refuges (deep ocean, low-energy zones) and repopulated afterward. Recovery of ecosystems was very slow , it took millions of years for biodiversity to bounce back. Because the extinction was so severe, many evolutionary groups that survived laid the foundation for Mesozoic life (dinosaurs, modern groups).