October 24, 2006 (ScienceDaily.com) – There’s growing evidence that the dinosaurs and most their contemporaries were not wiped out by the famed Chicxulub meteor impact, according to a paleontologist who says multiple meteor impacts, massive volcanism in India, and climate changes culminated in the end of the Cretaceous Period…

“The Chicxulub impact could not have caused the mass extinction,” says Princeton University paleontologist Gerta Keller, “because this impact predates the mass extinction and apparently didn’t cause any extinctions.”…

The Deccan volcanism did the nudging by releasing vast amount of greenhouse gases into the atmosphere over a period of more than a million years leading up tothe mass extinction. By the time Chicxulub struck, the oceans were already 3-4 degrees warmer, even at the bottom, she says…

What the microfossils are saying is that Chicxulub probably aided the demise of the dinosaurs, but so did Deccan trap volcanism’s greenhouse warming effect and finally a second huge impact that finished them off. So where’s the crater?

“I wish I knew,” said Keller. “There is some evidence that it may have hit in India, where a crater of about 500 kilometers in diameter is estimated and named Shiva by paleontologist Sankar Chatterjee from the Museum of Texas Tech University in Lubbock. The evidence for it, however, is not very compelling at this time.”

More… (source)

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