Research shows that dinosaurs got eliminated by a "one-two punch" of twin crises, not a single one.
Due to ancient climate change, the dinosaurs were shown as made weak by the huge volcanic eruptions in the regions that constitute India today. About 150,000 years later, another giant asteroid crashed on earth and wiped out the dinosaurs.
That was the end of the dinosaurs about 66 million years ago, decimating all of them except a few that became birds.
About ten of the 24 species vanished at an Antarctic island before the comet or asteroid hit the planet, while the other 14 were made extinct in a second wave.
About three-quarters of the earth's animal and plant species also became extinct. Even as the giant asteroid's impact at Chicxulub in the region known as Mexico led to their disappearance, it was also due to volcanic eruptions.
"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.
Ocean temperatures were constructed in Antarctica during the dinosaur extinction. Scientists analysed the composition of the fossil shells and were also surprised by warming spikes---the first at the same time as the Deccan Traps region, and the second during the Mexican meteor impact.
Researchers indicate that a "press-pulse" mechanism might have decimated the dinosaurs. Due to the "press" of gradual climate change, India's volcanic eruptions took place, after which the "pulse" of a massive asteroid hit the 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.
"A previous study found that the end-Cretaceous extinction at this location occurred in two closely timed pulses," Petersen said. "These two extinction pulses coincide with the two warming spikes we identified in our new temperature record, which each line up with one of the two 'causal events.'"
The study was published in Nature Communications.
