'Fast food' behind long neck dinosaurs' gigantism

Washington, May 12 (ANI): Gulping down food just like fast food to satisfy their huge appetite may well have been the reason behind the gigantism of long-necked dinosaurs, according to a new German research.

Researchers led by Professor Martin Sander from the University of Bonn have explained why today's terrestrial animals are nowhere near reaching the Jurassic size record.

While we chew, giant dinosaurs gulped.

Chewing helps to digest the food faster. By the grinding process it is broken down and at the same time its surface is enlarged. This way the digestive enzymes are able to attack the food more easily.

Sander said: "Chewing is a property of prototheria which no large herbivorous terrestrial mammal has got rid of."

But chewing requires time - a resource that becomes scarce with increasing size.

Also, the ones that chew need a large head, since molars and muscles have to be put somewhere.

However, the herbivorous giant dinosaurs had relatively small, light skulls. This enabled them to grow extremely long necks. And these again helped them to make food intake as efficient as possible. So they did not constantly have to heave their 80-ton body over the Jurassic savanna while looking for their greens.

They just remained on the spot and used their agile neck to browse their surroundings. This was particularly relevant for the heavy-weights. Smaller dinos simply had far smaller necks compared to their body length.

The digestion process itself probably took several days with the giant dinosaurs, due to the missing molars.

However, their stomachs were so large that they still provided them with enough energy round the clock.

Moreover, the metabolism of these giant animals was incredibly powerful. They possessed amazingly sophisticated lungs, which were far more effective than those of humans.

The large number of air sacs which permeated the body cavity and vertebra of the dinosaurs played an important role in their function.

Combined with a nifty system of valves they ensured that a gas exchange could take place while breathing in as well as while breathing out. A nice side effect was that the neck got significantly lighter this way.

This was important for the statics of the animals.

Sander said: "In the history of species the lungs of today's birds and of the giant dinosaurs have the same origin.

"This effective air exchange principle was invented about 230 million years ago."

This is consistent with the fact that the earth passed through an oxygen trough at the time.

The concentration only 12 to 15 per cent, i.e. a third less than today.

So being able to pick out the few oxygen molecules in the thin air as rapidly and well as possible was a huge advantage.

Sander added: "200 million years ago, an unparalleled combination developed of primitive traits, which were new in the history of evolution. This combination made these fascinating giants possible."

The study has appeared in 'Biological Reviews'. (ANI)