DINOS DIED OF COLD; EXTINCTION MYSTERY SOLVED

By HELEN MORROGH
28 February 2009
The Sun

THE dinosaurs' 200 millionyear reign on Earth may have been ended by a slight chill, top boffins now believe.

For years palaeontologists reckoned the huge reptiles became extinct when an asteroid hit earth and released intense heat, blasting them into history almost instantly.

But new research suggests this event killed off T-Rex and pals over a longer period of time by triggering a number of environmental disasters — including fires, dust clouds and a cooling of temperatures.

The gargantuan beasts may have died from inhaling poisonous fumes, starving — or even getting a COLD.

Professor Pascal Godefroit of the Royal Belgian Institute of Natural Sciences led the groundbreaking research team.

He said: "We have no remains of cold-blooded reptiles such as turtles, crocodilians and lizards in polar areas — which suggests it was too cold for them.

"It was a big surprise for us but it is a theory as to how it ended."

Asteroid

Since the 1990s it has been known that dinosaurs died off around 65 million years ago.

A crater 280km wide in Mexico's Yucatan Peninsula marked where the massive asteroid hit.

It was thought to have sparked worldwide fires that created immense heat, killing 80 per cent of the world's animal species — including dinosaurs.

But scientists are now using new methods to date when exactly the space-rock crashed and what its impact was.

And while it was originally believed dinosaurs were wiped out in an instant, the process may have taken up to 200,000 years.

Dr Claire Belcher of UCD's School of Biology and Environmental Science said: "An asteroid impact could have various consequences on life on earth.

"It would release a significant amount of thermal energy by hitting rock, which if vaporised would release dust into the atmosphere." This dust, and fumes from burning oil and coal formed by the asteroid smash, would have had catastrophic effects on wildlife.

Thick dust and soot could also have presented the sun's rays from getting through, making earth much colder over time.

Cooler temperatures could have killed these prehistoric monsters in different ways.

There would be far less vegetation for them to eat, temperatures could drop to a fatal level and the chance of them catching colds and viruses would increase.

How and why the dinosaurs perished has always been one of science's great mysteries.

There have been a number of theories as to why they disappeared off the face of the earth — including volcanoes, cannibalism and a plague of indigestion.

And a few wacky theorists have even suggested they died when flowering plants spread and evolved — causing the goliaths to die from HAY-FEVER.

helen.morrogh@the-sun.ie

Bug off ... tiny virus might have felled giants [I assume this was a picture caption -Ed]