The dinosaurs may have faced a mass extinction of their own, but new observations have concluded that their era of dominance was ushered in by another mass extinction before them - one that was the result of a volcanic tendency.
It seems that 200 million years ago, a series of massive volcanic eruptions may have been the driving force in the subsequent climate change that wiped out around half of the species on Earth (the End-Triassic Extinction). While volcanoes have been generally thought as the culprit, it isn't until this study, titled, "Zircon U-Pb Geochronology Links the End-Triassic Extinction with the Central Atlantic Magmatic Province," that a precise date was found. Scientists studied basalt samples from Morocco, Nova Scotia, and New York City and linked massive lava outpourings to a date around 201,564,000 years ago.
"This may not quench all the questions about the exact mechanism of the extinction itself. However, the coincidence in time with the volcanism is pretty much ironclad," said co-author Paul Olsen, a geologist at Columbia University's Lamont-Doherty Earth Observatory.
The 200 million-year-old eruptions spat out around 2.5 million cubic miles of lava during a 600,000 year time period. One can only imagine the ensuing environmental havoc, when many species simply couldn't adapt fast enough to such extreme conditions.
The researchers studied the decay of uranium in the basalt left by the eruptions to properly date more accurately the eruptions. The earliest eruption occurred in Morocco, followed by Nova Scotia, and finally New Jersey. Previous estimates had a margin of error of 1-3 million years. The new one? Only a few thousand years.
You can read the full published study in the journal Science.