CHARLOTTE, NC Researchers have discovered why plants and animals had a hard time recovering from the largest mass extinction in Earth's history 250 million years ago.
The reason: global warming.
Because of environmental consequences of rising temperatures, those species that survived the extinction didn't fully recover for 5 million years.
The study adds a new chapter to the story of how life was forever altered by giant volcanic eruptions in the Early Triassic period an event now called the "Great Dying" and offers clues as to how climate change might impact life today, said Ohio State University doctoral student Alexa Sedlacek, who presented the results at the Geological Society of America meeting in North Carolina this week.
"The lesson is, life doesn't just snap back," added Matthew Saltzman, professor of earth sciences at Ohio State and Sedlacek's advisor. "We've long known from the fossil record that there was a long period with very little recovery right after the Great Dying. It's as if life had a 5-million-year hangover. Now we know why."
Sedlacek and Saltzman analyzed sedimentary rock formed on a tropical ocean floor 250 million years ago. Chemicals they found in the rock confirm that after the volcanic eruptions of the Great Dying, huge amounts of the Earth's surface were being weathered away by greenhouse gases in the atmosphere. Earth's climate was chemically altered as a result.
The ocean was highly acidic, clogged with sediment and warm as a modern hot tub.
"People are understandably interested in the Great Dying because 90 percent of marine species went extinct," Sedlacek said. "But the recovery from that event is equally important, because the survivors determined what kind of life we have on Earth today."
"Extinctions are still happening today," she continued, "and though things were much worse back then, the greenhouse gases that were made by volcanoes are analogou
|Contact: Pam Frost Gorder|
Ohio State University