London, May 12 (Inditop.com) Why were the sauropod dinosaurs able to grow so much larger than today’s terrestrial animals?
A research group led by the University of Bonn (UB) seems to have solved this puzzle — that Jurassic fast food culture was a key to gigantism.
The giant dinosaurs did not chew their food — they just gulped it down, say the results of the researchers’ years of work.
There is a simple rule of thumb. The larger an animal is, the more time it spends eating. This means an elephant hardly has time to sleep. It spends 18 hours every day satisfying its huge appetite.
“This led us to one of the many riddles that gigantism of dinosaurs puts before us,” says Martin Sander, professor at the UB.
“They were just so large that a day would have had to have 30 hours so that they were able to meet their energy demands,” he says.
Sander is a spokesman for an international research group which is looking for explanations for this and other paradoxes.
The Deutsche Forschungsgemeinschaft (German Research Foundation) has funded the project to date with three million euros.
For the first time, their research is offering a plausible answer to the question which the group sought to answer six years ago: why the giant long-neck dinosaurs were even able to exist.
The researchers also explain why today’s terrestrial animals are nowhere near reaching the Jurassic size record. One reason is that 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.
“Chewing is a property of prototheria (subclass of mammals) which no large herbivorous terrestrial mammal has got rid of,” Sander says.
But chewing requires time — a resource that becomes scarce with increasing size. At the same time the following is true: the ones that chew need a large head, since molars and muscles have to be put somewhere. Not without reason elephants are quite big-headed.
However, the herbivorous giant dinosaurs had relatively small, light skulls. This fact 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-tonne 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, said an UB release.
This was particularly relevant for the heavyweights. Smaller dinosaurs simply had far smaller necks compared to their body length.
These findings are slated for publication in Biological Reviews.
