Researchers seem to keep finding new ways that most of the planet's life could have gone extinct.
Researchers at the Nordic Center for Earth Evolution at the University of Copenhagen claim to have discovered the cause of the extinction of over half the Earth's marine life 200 million years ago, reports Fox News. The cause, it seems, was a giant "Earth burp."
That is, a huge quantity of methane being released into the atmosphere.
The methane release likely originated from the sea floor, according to the study, and added a huge amount of carbon to the atmosphere, killing many species. LiveScience reports that the find suggests this event killed a number of species, paving the way for the rise of the dinosaurs.
The gas was releases over a period of 600,000 years, according to the report.
Scientists came to this conclusion by analyzing the chemical content of plant leaves preserved in the sediment at the bottom of the Tethys Ocean. By studying the different carbon isotopes in the sediment, scientists were able to draw these conclusions, reports LiveScience.
The researchers found a peak in favor of the lighter isotope, carbon 12, for a stint lasting about 20,000 to 40,000 years.
A strong shift in the ratio indicated that methane, not carbon dioxide, was responsible, Ruhl said.
In the past, scientists believed the reason for this extinction could be linked to an increase of carbon dioxide in the atmosphere.
However, this doesn't change any theories about how the dinosaurs went extinct. Last month scientists uncovered further evidence to suggest that they were killed by a meteorite, and were roaming Earth at the time of impact.
There are a wide range of other mass extinction theories, including the idea that the Yellowstone supervolcano may have spread similar gases into the atmosphere that wiped out numerous species.