Tyrannosaurus Rex, Prehistoric ATUSA/ Museums Source: News Corp Australia

At the beginning of the 1980s the mystery of what caused the mass extinction of the dinosaurs was still very much unanswered. By the end of the decade, the discovery of a huge impact crater off the coast of Mexico led the scientific community to unanimously endorse one theory: A giant asteroid had slammed into earth causing a deep freeze that killed off the Jurassic creatures.

But new evidence shows that there was another environmental catastrophe that was occurring at the same time. A series of volcanic eruptions that eclipse anything seen by humans may have also played a role in bringing about the demise of the dinosaurs.

According to the study, these eruptions were so powerful they left nearly 518,000 sq kilometres of what is now India, buried in volcanic basalt over two kilometres thick.

There is little doubt that an asteroid killed off the dinosaurs, but it may have had some help. Source: NASA Source: Supplied

Many scientists now postulate that this indeed played a role in the extinction of the dinosaurs — it’s just a question of what impact it had.

“We can now say with confidence,” says Blair Schoene, a Princeton geologist and lead author of the paper, “that the eruptions started 250,000 years before the extinction event, and lasted for a total of 750,000 years.”

That knowledge, according to the geologist, gives credence to the idea that the volcanoes contributed to the mass extinction of multiple species.

Any attempt to understand incidents that occurred over 65 million years ago is going to be difficult and unsurprisingly there remains a lot of uncertainty about the exact details of how the volcanoes brought about such inhospitable conditions.

Volcanoes emit carbon dioxide, which could have triggered an intense burst of global warming, but they also emit sulfur dioxide, which could have caused global cooling.

“What we do know,” Schoene says, “is that earlier mass extinctions were caused by volcanic eruptions alone.”

We continue to discover more and more about the lives of the dinosaurs. Source: News Limited

While the new study provides some compelling evidence, not every palaeontologist is convinced of its significance.

Brian Huber, of the Smithsonian Institution, welcomes the dating of the eruptions which were based on widely accepted uranium-lead measurement techniques, “that part of the science is great,” he said.

However, Mr. Huber takes issue with the link between the eruptions and the extinction of species and feels that the pre-existing theory is of asteroid impact is significantly more robust.

“The case of the mass extinctions being caused by an impact is overwhelming,” he said.