Dinosaurs died from sudden temperature drop 'not comet strike', scientists claim

Dinosaurs were wiped out by sudden drop in temperatures, not by comet striking the planet, scientists claimed.

By Andrew Hough
Published: 8:00AM BST 24 Apr 2010

British researchers claim that a sudden plummeting in the sea temperature of 16F (9C) more than 137 million years ago was the first step towards their eventual road to extinction.

While studying fossils and minerals from the Arctic Svalbard, Norway, they concluded the sudden change in the Atlantic Gulf Stream during the Cretaceous period would almost certainly have wiped out the ''abundance'' of the world's dinosaurs.

Some experts believe the creatures were wiped out by one cataclysmic event 65 million years ago – such as a meteor hitting the planet.

But the new research suggests they were wiped out by a series of environmental changes, starting with a drop in sea temperatures.

Gregory Price, from Plymouth University, who led the study, said his team's research showed the drop in temperature happened when the Earth was in a ''greenhouse'' climate, which was very similar to now.

He found the drop in temperatures was so severe that numerous species of dinosaur previously living in warm, shallow seas, land and swamps would have died out.

''We believe dinosaurs were most likely to be cold-blooded creatures and would have needed the warmth to keep them alive,” he said.

“If they were unable to migrate south they could have been wiped out. Climate change is now very much on the agenda in trying to determine how the dinosaurs became extinct.

“We now believe that they died out gradually and it is very possible that this could have been caused by a series of climatic changes.''

The drop in temperature is thought to have occurred because high levels of CO2 were in the atmosphere which caused global temperatures to rise and polar ice to melt – a phenomenon currently predicted for Earth.

http://www.telegraph.co.uk/science/dinosaurs/7624014/Dinosaurs-died-from-sudden-temperature-drop-not-comet-strike-scientists-claim.html