A few months ago we told you about a toothy new dinosaur that gulped down its food whole without chewing. Now new details about this ultimate dinosaur fast food lifestyle are coming in. They help to explain why some dinosaurs grew to become so tall, long and fat.

Research in the journal Biological Reviews presents a common sense bit of truth: The larger an animal is, the more time it spends eating. Elephants, for example, spend 18 hours per day satisfying their voracious appetites.

Since dinosaurs couldn't add hours to their daily schedule, they evolved their ability to gulp down food whole. Chewing involves a more sophisticated process, since it allows food to digest faster. When you break food down into tiny bits with your teeth, the total surface area of what's swallowed increases, permitting digestive enzymes to more easily process the food.

The main problem with chewing is that it requires a lot of time and energy. The largest sauropod plant eaters also had relatively small heads at the end of long necks. A skull permitting heavy muscle and bone, suitable for chewing, would not have worked well given such a body design. The large necks allowed the dinosaur giants to grab food with ease, instead of having to heave what was often an 80-ton body over the Jurassic savanna while looking for greens. A huge sauropod could have just stood still while moving only its neck to feed.