New research presented at the Geological Society of America's meeting in Denver on October 26, 2026, suggests that three of Earth's five famous mass extinctions stretched over millions of years rather than striking as sudden catastrophes. The finding comes from an AI model trained on fossil records, and it throws a wrench into decades of textbook science.
According to Popular Mechanics, Shuzhong Shen of Nanjing University in China built a transformer-based AI model called OneStrata to sharpen the fossil timeline from blurry million-year bins down to a resolution of roughly 1,000 years. The model was trained on the OneStratigraphy dataset, a massive collection of fossil information, and works much like a language model predicting the next word, except it predicts where fossils fall in the rock record.
What the AI actually found
The analysis indicates that the Late Devonian, end-Triassic, and end-Cretaceous extinctions unfolded over millions of years, not in the geological blink of an eye. Only the end-Permian event, which wiped out most life in roughly 63,000 years, fits the classic picture of a rapid collapse.
That lines up with Shen's earlier work. In 2020, he and a team of Chinese scientists used a supercomputer to reach a resolution of about 26,000 years, drawing on 11,000 marine fossils from more than 3,000 stratigraphic sections. That study showed the Late Devonian extinction, around 360 million years ago, played out gradually, with biodiversity declining over roughly 50 million years.
Shen cautions that the new output is a biodiversity curve. Species may have been going extinct while others quickly took their place, which means the word 'extinction' itself may need a second look.
Why scientists can't even agree on what a mass extinction is
Even the definition is up for grabs. As Naked Capitalism noted in a recent book essay, Professor Harper argues early in the book that 'The Sixth Extinction is more of a provocation than a settled fact.' Estimates of how many mass extinctions Earth has actually experienced range from three to as many as 20, according to New Scientist reporting cited by Popular Mechanics.
Much of the confusion comes from how the data has been handled. Stratigraphers traditionally group fossil specimens into time spans of millions of years. That makes the mountain of data manageable, but it smears the timeline and hides what happened at shorter intervals, exactly the scale where real ecological drama unfolds.
The sixth extinction debate, and why skepticism is healthy
Plenty of voices insist we are living through a sixth mass extinction right now, driven by human activity. DW reports that the rate at which species are disappearing today suggests Earth is experiencing a sixth event. Some researchers go further: ScienceDaily covered new findings suggesting Earth might actually be in its seventh mass extinction, with the first such event occurring millions of years earlier than scientists previously realized.
Here is the honest takeaway. When the experts cannot agree on whether we face extinction number six, number seven, or something in between, and when fresh AI analysis says most of the original Big Five did not happen the way the textbooks claim, Americans have every reason to greet sweeping doom-and-gloom policy demands with a healthy dose of doubt. Science is supposed to question itself. This study is a perfect example of that process working as intended.
Hard data beats hype
There is a lesson here about letting evidence, not alarmism, drive the conversation. For decades, schoolchildren were taught that an asteroid killed the dinosaurs overnight and that four other sudden catastrophes reshaped life on Earth. Now a machine learning model, crunching more fossil data than any human could, says the story is far messier and slower.
That does not mean catastrophe is impossible. The end-Permian event really was fast and truly was devastating. But it does mean the fossil record rewards careful study over lazy assumptions, and that even the loudest scientific consensus deserves to be challenged with better tools and better data.
Shen's team plans to keep refining the model's resolution. Millions of years from now, today's debates may look like another blurry chapter in Earth's stratigraphic story, but for now, OneStrata has reset the conversation about how life on this planet rose, fell, and rose again.
FAQ
Which mass extinctions did the AI study say were gradual?
The study found the Late Devonian, end-Triassic, and end-Cretaceous extinctions unfolded over millions of years rather than as sudden events.
What is OneStrata?
OneStrata is a transformer-based AI model built by Shuzhong Shen at Nanjing University, trained on the OneStratigraphy fossil dataset to place fossils in time with a resolution of about 1,000 years.
Which mass extinction was actually fast?
The end-Permian extinction stands out. Most life disappeared in roughly 63,000 years, according to the research.
Are we in a sixth mass extinction now?
Scientists disagree. Estimates of the number of mass extinctions range from three to as many as 20, and some recent research argues Earth may even be in its seventh such event.