Largest extinction event on Earth most likely killed plants first

Washington: A new research led by the University of Nebraska-Lincoln says that plants may have suffered the wrath of Great Dying long before their animal counterparts.

About 252 million years ago, the planet’s continental crust was mashed into the supercontinet Pangea and volcanoes in modern-day Siberia began erupting. This caused carbon and methane to be spewed into the atmosphere for roughly 2 million years causing 96 per cent of oceanic life and 70 per cent of land-based vertebrates to be wiped off the planet.

The new study now finds that a by-product of the eruption, drove some plant life to extinction nearly 4,00,000 years before most marine species were killed off.

Speaking about the study, lead author Christopjer Fielding said that while people have always hinted at something similar, no one before them has been able to pin it down.

The researchers reached the conclusion by studying fossilised pollen, the chemical composition and age of rock, and the layering of sediment on the southeastern cliffsides of Australia.

They found surprisingly high concentrations of nickel in the Sydney Basin’s mud-rock – surprising because there are no local sources of the element.

Tracy Frank, professor and chair of Earth and atmospheric sciences, said the finding points to the eruption of lava through nickel deposits in Siberia.

That volcanism could have converted the nickel into an aerosol that drifted thousands of miles southward before descending on, and poisoning, much of the plant life there. Similar spikes in nickel have been recorded in other parts of the world, she said.

If true, the phenomenon may have triggered a series of others: herbivores dying from the lack of plants, carnivores dying from a lack of herbivores, and toxic sediment eventually flushing into seas already reeling from rising carbon dioxide, acidification and temperatures.