The dinosaurs were not wiped out by a comet or asteroid impact or some other planetary catastrophe but by a serious flatulence problem, according to research quoted in a Chinese news report.

Dinosaur wind contained a high proportion of methane gas - powerful enough to damage the ozone layer, said the China Youth Daily quoting a French scientist.

"The animals, weighing from 80 to 100 tonnes, would eat on average between 130 and 260 kilos of food every day. They would fart non-stop," said the traditionally austere paper.

During the dinosaurs' time on Earth, "the atmosphere became charged with methane, which finally damaged the ozone layer and brought about great changes in the vegetation," it added.

The changes caused a food shortage that eventually wiped out the great reptiles.

The ozone layer protects living things on the Earth's surface from the Sun's ultra-violet radiation.

There are numerous theories as to why dinosaurs died out. The two most favoured theories involve:

• massive volcanic eruptions that unleashed poisonous gases and caused widespread climatic change;
• a large comet or asteroid striking the Earth, which threw up dust and debris into the atmosphere blocking sunlight and causing a dramatic change in climate.

China Youth Daily did not identify the French scientist behind the latest theory.