In 2017, USGS and MIT researchers dated a magma pulse to 251.9 million years ago. 9 years later, it links to Earth's worst extinction

About 252 million years ago, Earth experienced the most severe mass extinction in its history. An estimated 81% to 94% of marine animal species disappeared, while ecosystems on land also suffered a profound collapse.

The leading explanation points to the Siberian Traps, a vast region of volcanic activity formed through repeated pulses of magma. But the key question is not simply how much rock was produced. Scientists have also had to determine which phase of the volcanic activity coincided with the environmental crisis.

A 2017 study involving researchers from the USGS and MIT provided an important piece of that timeline. High-precision dating placed a major phase of Siberian Traps magmatism at about 251.9 million years ago, close to the timing of the end-Permian extinction.


The research also drew attention to magma moving underground through Siberia's sedimentary rocks. As the magma interacted with coal, hydrocarbons, carbonates, and evaporites, the heat could have released greenhouse gases and other volatile compounds, providing a possible pathway from the volcanic activity to widespread environmental disruption.

The extinction came before the dinosaurs

The end-Permian extinction marked the boundary between the Permian and Triassic periods, long before dinosaurs became part of Earth's ecosystems.

The oldest unambiguous dinosaur fossils are roughly 233 million years old, about 19 million years after the extinction. A 2026 analysis of early dinosaur evolution inferred that the dinosaur lineage itself may have originated between 250 million and 240 million years ago, but even that estimate places dinosaurs after the main crisis.

The world affected by the extinction was dominated by very different communities.

Permian oceans supported brachiopods, corals, ammonoids and many other lineages. On land, reptiles, amphibians and numerous synapsids occupied the continents. Synapsids are the evolutionary branch that would eventually produce mammals, although most Permian members looked very different from modern mammals.

The extinction removed much of that established biodiversity and left ecosystems severely disrupted.

Siberia did not erupt in one giant explosion

The Siberian Traps were not a single volcano producing one enormous eruption.

The province formed through repeated episodes of basaltic magma reaching the surface through long fractures. Lava spread across the landscape in enormous flows, while magma also moved underground through vertical dikes and horizontal sheets known as sills.

The resulting volcanic province was enormous. Estimates of its original volume vary because erosion removed some lava, later sediments buried other sections and much of the magma was emplaced underground.

A 2024 review of the Siberian Traps gives original-volume estimates ranging from roughly one million to 15 million cubic kilometres. A commonly cited range for intrusive and extrusive igneous rock combined is about seven to 15 million cubic kilometres.

But the amount of rock alone does not explain the extinction. The timing of the magma pulses and their interaction with surrounding rocks are also important.

The 2017 study narrowed the focus to underground magma

High-precision uranium-lead dating showed that major Siberian Traps magmatism occurred before, during and after the extinction. The entire volcanic episode therefore cannot simply be treated as one event responsible for the biological collapse.

The 2017 study of the province's underground sill complex provided a more specific connection. Researchers found that a major intrusive phase coincided with the beginning of the extinction and a sharp disturbance in the global carbon cycle.

When magma moved sideways through sedimentary rocks beneath Siberia, it encountered deposits containing coal, hydrocarbons, carbonates and evaporites. The intense heat could release carbon dioxide, methane and other volatile compounds.

This made the underground interaction between magma and sedimentary rocks an important part of the explanation for how volcanic activity in Siberia could produce environmental changes on a global scale.

How the volcanic crisis spread through the environment

Greenhouse gases released during the volcanic activity could drive rapid warming. Warmer oceans hold less dissolved oxygen, while changes in circulation can make it harder for oxygen to reach deeper waters.

Acidification added another pressure, particularly for organisms that built shells and skeletons.

Volcanic sulfur, halogens and metals may also have contributed to acid rain, toxic contamination and ozone damage. On land, wildfire and soil erosion could further disturb ecosystems and send nutrients into coastal waters, worsening oxygen loss.

The crisis therefore involved several environmental stresses rather than one single mechanism.

A 2018 climate and ocean model reproduced much of the geographic pattern of marine losses through the combined effects of warming and oxygen depletion. A separate high-resolution study of sediments in China found evidence of wildfire, soil disturbance and oxygen-free, sulfide-rich marine conditions immediately before the main extinction interval.

Different ecosystems could therefore have experienced different immediate causes while responding to the same broader volcanic crisis.

The “90%” figure needs some context

The end-Permian extinction is often described as killing about 90% of marine life, but that figure is an estimate rather than a precise count.

Scientists reconstruct extinction rates from fossils, and the result depends on sampling, taxonomy and statistical corrections for gaps in the geological record.

A 2026 synthesis of marine recovery puts the current estimate at between 81% and 94% of marine animal species lost.

The upper end of that range is close to the commonly used “90%” description. It refers to species, not 90% of every individual animal alive at the time.

Even the lower end represents an extraordinary collapse. Roughly four out of every five marine animal species would have disappeared.

Entire reef-building groups vanished, food webs were simplified and the dominant communities of the Paleozoic oceans were fundamentally changed.

The crisis continued after the main extinction

The end-Permian extinction was followed by a difficult recovery.

Magmatism continued after the main extinction interval, while early Triassic climates remained extremely hot and unstable. Ocean chemistry also stayed hostile in many environments.

Some simple and opportunistic communities appeared relatively quickly, but rebuilding complex ecosystems took much longer.

The prolonged recovery shows that the event was more than a brief loss of species. The catastrophe changed ecological relationships, leaving predators without prey, reefs without their builders and surviving lineages in ecosystems with empty ecological roles.

Why the 251.9-million-year date matters

The significance of the 2017 research lies in the timing. Dating a major intrusive phase to about 251.9 million years ago placed it close to the beginning of the end-Permian extinction and alongside a major disruption of the carbon cycle.

That timing strengthened the connection between Siberian magmatism and the environmental crisis. It also helped shift attention toward the underground sill complex and the sedimentary rocks it heated. The volcanic story was not only about lava reaching the surface. The interaction between magma and surrounding rocks may have been crucial to the gases released during the event.

The end-Permian extinction was a cascading environmental crisis associated with an enormous period of volcanic activity. The 2017 dating helped identify when one of the potentially important intrusive phases occurred.

The basalt is what remains of the Siberian Traps. The extinction was what happened as Earth's climate, oceans and ecosystems responded to that geological upheaval.