Asteroid ended the age of dinosaurs

Washington, May 26 (ANI): A team of scientists claim to have finally concluded what ended the age of the dinosaurs - an asteroid.

The discovery of a massive crater at Chicxulub in Mexico's Yucatán Peninsula in 1991 strengthened that hypothesis.

The Chicxulub crater is more than 120 miles wide - about the distance from Fairbanks to the Arctic Circle - and scientists believe it was created when an asteroid more than six miles wide crashed into Earth 65 million years ago.

The cataclysmic impact - a million times more powerful than the largest nuclear bomb ever tested - triggered massive earthquakes, atmospheric discharge and oceanic upheaval.

The ensuing mass extinction ended both the reign of the dinosaurs and the Cretaceous period, which gave way to the Paleogene period.

This theory, having steadily accumulated evidence, was thought to be a near-consensus view.

Recently, however, in a series of articles, researchers posed an alternate hypothesis for the mass extinction.

Some scientists claim that long-term volcanic activity at the Deccan Traps, in what is now India, caused acid rain and global cooling, gradually making life untenable for the dinosaurs and other large animals.

They also suggest that the Chicxulub impact occurred some 300,000 years before the mass extinctions.

The alternate hypothesis spurred University of Alaska Fairbanks scientist Michael Whalen and other Chicxulub impact proponents to respond.

They argue that the geological record favors the Chicxulub impact event theory.

Whalen said: "It's as tight a case for a synchronous chain of events as we can find in the fossil record."

Whalen first began studying the Chicxulub site in 2002.

His analysis offered insight on the geography of the area prior to impact, how it changed during the impact and the eventual infill of the crater by limestones deposited after the impact event.

The research has appeared in the March 5 issue of the journal Science. (ANI)