Could a plant-eater chew its food?
Plant-eaters didn't have molars, like humans, and many could not chew. But some had toothless, horny beaks for snipping plants, as well as rows of teeth in their cheeks for grinding them down. Each tooth was coarsely serrated. Years of grinding tough plants wore teeth down. Those shown here are from an Iguanodon. One is in good condition; the other is worn.
Worn lower tooth
Worn lower tooth
Long claws for hooking plants
Were long necks useful?
. Some long-necked dinosaurs A probably lifted their heads to reach high up in the trees. Others, such as this Thecodontosaurus, may also have used them to reach into the middle of low-growing plants. Thecodontosaurus was a likely ancestor of the sauropods and had a much shorter neck than its later relatives.
Long claws for hooking plants n
Did plant-eaters swallow stones?
A These smooth stones, known as gastroliths, were recovered from the skeletons of various sauropods. Perhaps the dinosaurs had deliberately swallowed stones to aid their digestion. The stones might have stayed in a dinosaur's digestive system, grinding up the vegetation that it swallowed. However, it is more than likely that raw vegetation was broken down by special bacteria, as happens in the stomachs of cows.
As the plant-eaters' teeth wore down, new ones grew to replace them.
n Many of the plants that dinosaurs ate, such as ginkgo and ferns, are still common today.
Fish-eating sea creature Elasmosaurus had a neck 23 ft (7 m) long, half its body length. It probably used this long neck to ambush fish swimming above it.
Where did plant-eaters live?
During the 160 million years that dinosaurs existed, new landmasses appeared and different habitats were created. The herbivores, along with carnivores, lived in most of them, although tropical forest was a favored habitat for big sauropods. Some plant-eaters adapted to extreme conditions, while others may have moved on to find new lands. Whether in a forest or a windswept plain, many of the herbivores spent their lives with each other, perhaps even living in herds of thousands.
How had the landscape changed?
| A By the Cretaceous Period, the world's landmass was splitting into continents, which looked closer to those that we recognize today. New groups of dinosaurs arose in different places. The horned dinosaurs, for example, emerged in Asia, but crossed into North America, where they were able to flourish.
Cretaceous Earth m
Was this article helpful?