Dinosaur flatulence may have helped warm Earth's prehistoric climate, say scientists who studied the giant reptiles' fossilized dung.
The researchers detected chemical signs of bacteria and algae in known and suspected dinosaur droppings. That indicates plant-eating dinosaurs digested their food by fermenting it, a process that gives off methane.Methane is a "greenhouse gas," like the carbon dioxide exhaled by all animals and emitted by smokestacks. Such gases trap solar heat in the atmosphere, warming the planet just as glass traps heat inside a greenhouse.
"Gas from dinosaurs includes methane that may have been a minor contributor to global warming 75 million to 80 million years ago," said Simon Brassell, a geochemist at Indiana University in Bloomington.
Brassell said if scientists prove dinosaurs contributed to a prehistoric greenhouse effect, it would support the theory that modern global warming is aggravated by methane burped up by cattle, sheep and other livestock that ferment their food.
Brassell presented the findings in San Diego on Tuesday during the Geological Society of America's annual meeting. The study's other authors are geologist Karen Chin and Robert Harmon.
Other scientists questioned the findings.
"I wonder whether or not there were enough dinosaurs to make that substantial a contribution to atmospheric chemistry," said climatologist Eric J. Barron.