Dinosaurs vanished after double blow of volcanic eruptions in India and asteroid impact in Mexico
Latest research has revealed that dinosaurs were wiped out by a “one-two punch” of twin disasters. It was kind of a double whammy of bad luck as per the scientists. It was not a single catastrophe that killed of the massive beasts.
Ancient climate change evidence suggests that the dinosaurs were first weakened by massive volcanic eruptions in what is India today, and then about 150,000 years later, a giant asteroid that smashed into Earth killed them off totally. The twin blow caused their extinction about 66 million years ago. They wiped out all the creatures except the one that evolved into birds.
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Ten of the 24 species that disappeared at an Antarctic island did so long before the comet or asteroid hit the planet some 66 million years ago. The remaining 14 disappeared in a second wave of extinction.
During the strikes, about three-quarters of the Earth’s animal and plant species were also wiped out. The giant asteroid’s impact at Chicxulub in modern-day Mexico contributed to the disappearance of the dinosaurs. It was not the sole cause, though. The volcanic eruptions were the first impact to weaken the beasts. The study was published in Nature Communications.
“We find that the end-Cretaceous mass extinction was caused by a combination of the volcanism and meteorite impact, delivering a theoretical 'one-two punch,” Postdoctoral researcher in the U-M Department of Earth and Environmental Sciences, Sierra Petersen, told Michigan News.
The scientists reconstructed ocean temperatures in Antarctica during the time of the dinosaurs’ extinction by analysing composition of fossil shells. They were surprised by two warming spikes. The first coincided with volcanic eruptions from Deccan Traps volcanic region in India. The second one coincided with the Mexican meteor impact.
The researchers believe that during the volcanic eruptions, Antarctic’s ocean temperatures rose by 7.8 degree Celsius due massive amounts of heat-trapping carbon dioxide being released into the atmosphere. The second spike happened about 150,000 years later when the asteroid struck. However, this warming was smaller than the previous.
The research suggests a “press-pulse” mechanism could have killed off the dinosaurs. The “press” of gradual climate change happened because of India’s volcanic eruptions. This was followed by the “pulse” of the massive asteroid slamming into Earth.
“This new temperature record provides a direct link between the volcanism and impact events and the extinction pulses -- that link being climate change,” Peterson said.
