New research suggests dinosaurs grew really big by not chewing their food

Sauropods are an extinct type of dinosaur that had a long neck and ate vegetation. Sauropods weighed up to 80 metric tons and up to 23 feet tall. Scientists believe that Sauropods were such a large size to discourage large predators from eating them. How they kept their massive size remained mysterious. Herbivores(plant eaters) were thought to have very few teeth and were thought to have eaten their food whole. They browsed large areas without moving much because of their extremely long necks and consumed large quantities of vegetation in a short period of time.  Martin Sander a paleontologist at the University of Bonn in Germany stated that "You can only have this neck if you don't chew your food, otherwise your head would be full of teeth and too heavy to support."

 According to Paul Upchurch an expert on sauropods from the University College of London most paleontologists agree that feeding is the key to sauropod magnetism. In order to outgrow their predators sauropods would need two things large amounts of food and a way to reach their full size quickly. In order to survive, sauropods needed to reach their full size quickly. Their bones show that they would reach adulthood in 20 to 30 years which is quick by dinosaur time. This told scientists that they had a high metabolic rate and were warm blooded. If the sauropods did chew their food they would have had a mouth full of teeth and their fore a shorter neck. They would then not be able to consume as much food this way and would not be able to reach their full size. Therefore it is very likely that if the sauropods did chew their food they would have reached extinction before the mass extinction 65 million years ago.

Information was found here http://news.nationalgeographic.com/news/2008/10/081009-dinosaur-big.html