The long-necked plant-eating dinosaurs known as sauropods that lived about 150 million years ago appear to have been rather flatulent. New calculations put the combined methane production of the hulking beasts at 520 million tonnes (Tg). As a comparison the total global methane emissions in 2010 were 593 Tg of which only 395 Tg was anthropogenic.

Ruminants and the climate

Ruminant animals such as cows, sheep and deer have microbes in their stomachs that aid them in digesting their food. They do this by fermenting the bits of plant, with methane as one of the by-products leaving the animal from the rear-end.

In 2012 all animals combined were good for about 98 tonnes of methane production, a significant enough methane source to be of interest to climate scientists.

Sauropods and the climate

Since sauropods used similar microbes to help them digest their plant food, this set a team of researchers studying sauropod ecology to wonder what amount of methane their beasts of interest might have produced. Their findings can be read in today’s edition of Current Biology.

Not as much as all modern sources –both natural and man-made- combined, but still a close call with only a 73 Tg difference. But considering that both current methane emissions and those caused by sauropods are estimates [albeit the former perhaps a bit more accurate than the latter, considering the difficulty of estimating the flatulence of creatures that went extinct millions of years ago] the numbers might be even closer.

This leaves one wondering: was it a comet strike and the consequent cloud cover that cooled the Earth millions of years ago or was it the absence of a group of hulking flatulent dinosaurs?

© Jorn van Dooren | www.bitsofscience.org