Dinosaurs Might Have Survived the Asteroid, Had It Hit Almost Anywhere Else

Had the asteroid that doomed dinosaurs crashed nearly anywhere other than the coast of Mexico, they might not have gone extinct, researchers say.

Had the asteroid that hit Earth 66 million years ago struck nearly anywhere else, some dinosaurs — and perhaps other species like this flying reptile — might have survived, according to a new study. Mark Garlick, via Science Source

Dinosaurs reigned supreme for more than 160 million years. Their dynasty came to a cataclysmic close 66 million years ago when an asteroid crashed into the Yucatán Peninsula in Mexico at a site now known as the Chicxulub crater, paving the way for mammals — and eventually humans — to inherit the Earth.

But had the extraterrestrial impact happened nearly anywhere else, like in the ocean or in the middle of most continents, some scientists now say it is possible dinosaurs could have survived annihilation. Only 13 percent of the Earth’s surface harbored the ingredients necessary to turn the cosmic collision into this specific mass extinction event, according to a study published Thursday in the journal Scientific Reports.

“I think dinosaurs could still be alive today,” if the asteroid had landed elsewhere, Kunio Kaiho, a paleontologist from Tohoku University in Japan and lead author on the study, said in an email.

Other researchers questioned their findings.

When the asteroid, which had a diameter about half the length of Manhattan, struck the coast of Mexico, it found a rich source of sulfur and hydrocarbons, or organic deposits like fossil fuels, according to the researchers. Scorching hot temperatures at the impact crater would have ignited the fuel. The combustion would have spewed soot and sulfur into the stratosphere in sufficient quantities to blot out the sun and change the climate, setting into motion the collapse of entire ecosystems and the extinction of three-quarters of all species on Earth.

A shaded relief image from NASA of the Yucatán Peninsula, showing the Chicxulub impact crater at upper left. NASA/JPL

The Chicxulub impact spewed an extraordinary amount of black carbon, or soot, from the rocks, the researchers said. That in turn launched nearly 60 Hoover Dams worth of soot into the upper atmosphere, cooling the Earth’s surface by as much as 18 degrees Fahrenheit, they said.

Not every place on the planet has the same amount of fossil fuel reserves and sulfur trapped beneath its surface. Locations with less hydrocarbons would have jetted less soot into the sky upon impact and created a smaller cooling effect around the globe. So Dr. Kaiho set out to determine the mass extinction hot spots in the Mesozoic real estate market.

The scientists now find the asteroid that wiped out the dinosaurs happened to hit an unlucky spot — had it landed in about 87 percent of anywhere else on Earth, the mass extinction might not have occurred. "The probability of the mass extinction occurring was only 13 percent," said study lead author Kunio Kaiho, a geochemist at Tohoku University in Sendai, Japan.

The scientists ran computer models simulating the amount of soot that asteroid impacts would have generated depending on the amount of hydrocarbons in the ground. They next estimated the climate effects caused by these different impact scenarios.

The researchers calculated the level of climate change needed to cause a mass extinction was a 14.4 to 18 degrees Fahrenheit (8 to 10 degrees Celsius) drop in global average surface air temperatures. This would involve an asteroid impact sending 385 million tons (350 million metric tons) of soot into the stratosphere.

The scientists found that a mass extinction would have occurred from the impact only if it had hit 13 percent of the surface of the Earth, including both land and oceans. "If the asteroid had hit a low- to medium-level hydrocarbon area on Earth, occupying approximately 87 percent of the Earth's surface, mass extinction could not have occurred," Kaiho told Live Science.

The scientists are also analyzing the level of climate change "caused by large volcanic eruptions that may have contributed to other mass extinctions," Kaiho said. "It is hoped that the results will lead to further understanding of the processes behind those mass extinctions."