AI model trained on millions of fossils challenges 'big five' extinction story

Overview

Updated 1 hour ago

An artificial-intelligence model trained on nearly four million fossils suggests three of Earth's 'big five' mass extinctions unfolded gradually, not as sudden cataclysms. The model, called OneStrata, reconstructs biodiversity changes across hundreds of millions of years at finer resolution than any previous global record.

The finding challenges a framework paleontologists have used for decades. If it holds, the Late Ordovician, Late Devonian, and end-Permian events were slow declines. The story of how life responds to environmental stress would need revision.

Why it matters

The model could rewrite when and how Earth's worst extinctions unfolded, reshaping how scientists understand biodiversity collapse today.

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Key Indicators

4 million

Fossils in training set

The OneStrata model was trained on nearly four million fossil specimens.

3 of 5

Extinctions possibly gradual

The model suggests the Late Ordovician, Late Devonian, and end-Permian events were gradual declines.

26,000 years

Resolution of 2020 analysis

An earlier supercomputer run achieved 26,000-year resolution for 11,000 marine species over 300 million years.

Voices

Curated perspectives — historical figures and your fellow readers.

Ever wondered what historical figures would say about today's headlines?

People Involved

Shuzhong Shen

Lead researcher, OneStratigraphy and OneStrata

Active in paleontological research

Organizations Involved

Nature

Scientific journal

Published the OneStrata findings

Peer-reviewed scientific journal that published the OneStrata model report on October 20, 2026.

OneStratigraphy

Research dataset project

Active, ongoing compilation

Global dataset of fossil and geological data compiled by Shen and colleagues over two decades.

Timeline

2006 October 2026

3 events Latest: Today

October 2026
Nature reports OneStrata model findings
Today Publication

Nature reports that an AI model trained on nearly four million fossils suggests three of the Big Five mass extinctions were gradual declines.
Today
2020
Supercomputer analysis sharpens extinction timeline
Research

Shen and colleagues run an algorithmic method on a supercomputer, achieving 26,000-year resolution for 11,000 marine species over 300 million years.
2020
2006
OneStratigraphy dataset compilation begins
Research

Shen and colleagues begin compiling fossil and geological data from tens of thousands of sites worldwide, a project spanning two decades.
2006

Scenarios

Gradual extinction view gains broad acceptance

Possible Resolves by End of 2028

Discussed by: Nature report and paleontologists cited in it

Follow-up studies using OneStrata or similar AI approaches confirm the gradual-decline pattern for the Late Ordovician, Late Devonian, and end-Permian events. The model's timeline becomes the standard reference for deep-time biodiversity.

Local records challenge the model

Possible Resolves by End of 2028

Discussed by: Researchers cited in the Nature report who note existing high-resolution local reconstructions

Paleontologists with detailed local records push back, arguing OneStrata's global averaging obscures sudden events visible at specific sites. A published rebuttal shows a specific extinction was sudden at a well-documented location.

Debate continues without resolution

Uncertain Resolves by End of 2028

Discussed by: The broader paleontology community

Both sides publish supporting evidence, and no consensus emerges. The field remains divided as more data accumulates.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

December 2001

Paring Down the Big Five (2001)

Science published an article by Richard Kerr questioning whether all five of the 'Big Five' mass extinctions were truly distinct events. Kerr noted that some of the five might not qualify as separate mass extinctions.

Then

The article sparked debate but the Big Five framework remained standard.

Now

The framework persisted, but the debate over what counts as a mass extinction continued.

Why this matters now

Shows the Big Five framework has been questioned before, setting the stage for the OneStrata challenge.

2024

End-Permian land-sea timing debate (2024)

Robert Gastaldo and colleagues at Colby College published research from South Africa's Karoo Basin showing the end-Permian extinction of land life happened hundreds of thousands of years before the marine extinction, and gradually.

Then

The findings contradicted the long-held view that land and sea life perished together.

Now

Raised questions about the sudden-cataclysm narrative of the largest mass extinction.

Why this matters now

Directly challenges the sudden-cataclysm view of the end-Permian, the same event OneStrata suggests was gradual.

1980

Alvarez asteroid hypothesis (1980)

Luis and Walter Alvarez and colleagues published evidence of an iridium layer at the Cretaceous-Paleogene boundary, linking the end-Cretaceous extinction to an asteroid impact.

Then

The hypothesis was controversial for years before gaining acceptance.

Now

Transformed understanding of the end-Cretaceous extinction and showed how new evidence can rewrite extinction narratives.

Why this matters now

Demonstrates how new evidence can fundamentally change the story of a mass extinction, as OneStrata may do for three of the Big Five.