Like huge cows, the mighty sauropods would have generated enormous quantities of methane.
Sauropods, recognisable by their long necks and tails, were widespread around 150 million years ago.
They included some of the largest animals to walk the Earth, such as Diplodocus, which measured 150 feet and weighed up to 45 tonnes.
Scientists believe that, just as in cows, methane-producing bacteria aided the digestion of sauropods by fermenting their plant food.
''A simple mathematical model suggests that the microbes living in sauropod dinosaurs may have produced enough methane to have an important effect on the Mesozoic climate,'' said study leader Dr Dave Wilkinson, from Liverpool John Moores University....