Scientists say that a million year-long of intense volcanic activities that took place over 200 million years ago may have been responsible for the rise of dinosaurs.
To arrive at this conclusion, the researchers studies ancient rocks and came across traces of massive emissions calculated to have taken place 200 million years ago.
The huge volcanic activities must have led to one of the largest extinction cases on Earth’s history, paving the way for dinosaurs to dominate the planet.
The study lead author Lawrence Percival of the Earth sciences department at Oxford University said that adapted to residing in the ecological niches that had been emptied by the extinction.
This study has been published in the journal PNAS.
The study involved looking into volcanic rocks from 4 different continents existent at these turbulent times.
This research is supported by one other that assessed the fluctuation of carbon in the rocks, an occurrence attributed to increase in carbon dioxide from volcanic eruptions.
However, the country study had a different point of view, checking the presence of mercury.
Every time there is a volcanic eruption, traces of mercury can be found in the plumes of gas that rise up in the sky. This is spread out by the wind, enjoins into sediments and falls onto the ground where it stays for millions of years.
Mr Percival explains that if you are able to spot a big spike in mercury, then you can confidently infer that volcanism is taking place at this exact time.
“And that’s what we see at the time of this extinction,” he adds.
In the course of the study, the researchers came across satisfactory evidence that indeed there were volcanic eruptions that went on for a million years.
Some of the evidences found included fissures, cracks in the Earth’s crust and ‘some fire mountains’ in addition to lava flows.
“You probably had different areas active at different times during the million years. And you likely get eruptive periods going on for a decade or so with enormous volumes of magma coming to the surface and gases as well,” says Professor Tamsin Mather of Oxford University.
Tough Times for Living Creatures
Any living creature closure to the eruptions site must have fared badly. But those farer away were not spared either since the eruptions had a devastating effect on the environment, including increase in Carbon dioxide levels and blocking out the Sun.
These circumstances then set the stage for massive wipe outs of animals such as early amphibians, reptilian-looking mammals and crocodile-like creatures.
But the same couldn’t be said for the dinosaurs. They clung onto life, even though the researchers are not able to explain how they managed to survive in the hellish conditions.
After the environment began to restore normalcy, very few of their competitors lived on, paving for rise of dinosaurs.