EXTINCTIONS × EARTH

The Extinction Before the Great Dying

~262 to 259 million years ago

Phanerozoic · Paleozoic · Permian

Eight million years before the end-Permian catastrophe, tropical shallow water in the eastern Tethys lost most of its corals, its reef-building foraminifera and its brachiopods, while an enormous volcanic province erupted through what is now southwest China. Mercury released by those eruptions turns up in the sediments, in pulses.

Why it matters

Treat it as the rehearsal: the same supercontinent, the same kind of trigger, a tenth of the scale. Two crises that resemble each other, eight million years apart, are how the link between flood volcanism and mass extinction gets tested instead of assumed. So far the test gives coincidence in time, which is not yet a mechanism.

Dating & uncertaintyDisputed

Whether this is one event or a series of closely spaced crises is unsettled, and so is its size: some records show a gradual decline through the Capitanian rather than a sharp loss. Mercury spikes and revised uranium-lead dates tie it to pulses of the Emeishan eruptions, but the tie is a coincidence in time, not a demonstrated mechanism.

Sources

1. Wignall et al. (2009), Science · Volcanism, mass extinction, and carbon isotope fluctuations in the Middle Permian of China
2. Ling et al. (2023), Chemical Geology · The Emeishan large igneous province eruption triggered coastal perturbations and the Capitanian mass extinction: insights from mercury in Permian bauxite beds
3. Wei et al. (2026), Geological Society of America Bulletin · Pulsed volcanism of the Emeishan large igneous province caused the Guadalupian (Middle Permian) mass extinction

Earth history as one day

22:36:531 h 23 min before midnight

if Earth’s 4.54 billion years were compressed into a single day