Creationist theory notwithstanding, dinosaurs roamed the planet for about 160 million years. They were present on every continent and completely dominated Earth’s environment. Then suddenly, 65 million years ago, most of them vanished. Why?
Climate Change Causes Extinction
Among paleontologists it is widely accepted that a fairly sudden climate change was behind the mass extinction of life forms that took place about 65 million years ago.
The hypothesis suggests that the climate change caused vegetation to die off, with catastrophic consequences for the large herbivorous dinosaurs. In turn, the carnivorous dinosaurs that preyed on the herbivores lost their source of food and died off as well.
What is not agreed upon so widely is what caused the climate change.
Asteroid Impact in Mexico
The asteroid impact theory is popular; this says that about 65 million years ago, a large asteroid slammed into Earth. The asteroid was about 10 kilometres in diameter and it slammed into what is now Mexico, at Chicxulub, on the Yucatan Peninsula.
The collision carved out a crater about 180 kilometres in across and, says the University of California Museum of Paleontology its impact threw “up enough dust to cause the climatic change…the environment changed from a warm, mild one in the Mesozoic [period] to a cooler, more varied one in the Cenozoic.”
Crater in India Challenges Earlier Theory
Dr. Sankar Chatterjee of Texas Tech University has found a crater in India that is far bigger than the one in Mexico. Reporting on the find, The Economist (October 24, 2009) says Chatterjee’s crater “is 500 kilometres across. The explosion that caused it may have been 100 times the size of the one that created Chicxulub. He calls it Shiva, after the Indian deity of destruction.”
He points to an underwater mountain off the coast of Mumbai as further evidence that some sort of apocalyptic event took place. The peak of Bombay High stands about five kilometres above the seabed and it sits within the rim of the Shiva crater. Dr. Chatterjee suggests that this mountain was formed by magma that spewed out of a crack in the Earth’s crust. That fissure, he says, was caused by the massive impact of a large asteroid.
Dr Chatterjee outlined his research on Shiva at the annual meeting of the Geological Society of America in Portland, Oregon, on October 18, 2009.
Volcanic Action Added to Climate Change
A press release from the Geological Society of America from two years earlier (October 29, 2007) suggests another scenario: “A series of monumental volcanic eruptions in India may have killed the dinosaurs 65 million years ago, not a meteor impact in the Gulf of Mexico.”
Left behind by this volcanic action are the massive Deccan Traps beds of lava in India. This geological feature is formed by multiple layers of basalt that cover an area of 500,000 km2 (about the size of Spain) to a depth of more than 2,000 metres.
Princeton University paleontologist Gerta Keller has been studying the Deccan Traps and she has calculated that the volcanic eruptions that produced them “released ten times more climate altering gases into the atmosphere than the nearly concurrent Chicxulub meteor impact.”
Dinosaurs Hit by Three Calamities
These three events – the Chicxulub Asteroid, the Shiva Asteroid, and the Deccan Traps volcanic action – all occurred at about the same time in geological terms, and just prior to the disappearance of the large reptiles.
The dinosaurs and the other life forms that were wiped out with them could not survive such a devastating triple whammy.
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