Is Earth staring down a mass extinction? Recent research from an international team of scientists reveals warning signs for the biggest mass extinction in our planet’s history were apparent far earlier than experts had thought — and we can glimpse such indicators now.

Paratirolites, ammonoids, fossils, fossil, Permian-Triassic, Permian, Triassic

Around 250 million years ago, the Permian-Triassic mass extinction saw about 90 percent of animal species eradicated, according to the University of Erlangen-Nürnberg in Germany, which led the research team. Huge volcanic eruptions and resulting greenhouse gas emissions wiped out scores of creatures. And for decades, scientists thought this so-called mother of all disasters occurred without warning “when seen on a geological time-scale,” the university said. This new research challenges that opinion.

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Fossils in Iran hint that the first indicators of the mass extinction appeared as early as 700,000 years before the event itself. Multiple species of ammonoids, an extinct group of marine animals, died off and surviving ones “became increasingly smaller in size and less complex” as time marched towards the mass extinction event, according to the university.

Factors that led to the event are reminiscent of conditions today, according to professor and lead author Wolfgang Kiessling, who said in the statement, “There is much evidence of severe global warming, ocean acidification, and a lack of oxygen. What separates us from the events of the past is the extent of these phenomena. For example, today’s increase in temperature is significantly lower than 250 million years ago.”

Even so, warning signs that were present near the Permian Period’s end can be seen in modern times, according to the university. Kiessling said, “The increased rate of extinction in all habitats we are currently observing is attributable to the direct influence of humans, such as destruction of habitat, over-fishing, and pollution. However, the dwarfing of animal species in the oceans in particular can be quite clearly attributed to climate change. We should take these signs very seriously.”

Geology published the work earlier this year; scientists from institutions in Germany, the United Kingdom, and Iran contributed.

+ University of Erlangen-Nürnberg

+ Geology

Images via Dieter Korn