Page 89 - The Dinosaur Book and Other Wonders of the Prehistoric World (DK-Smithsonian)

JAW MOVEMENT

Most modern plant-eating animals
chew their food. This involves grinding Jaw closing
their teeth together using complex jaw muscles were
Camarasaurus’s movements—up and down, side to side, attached
long, peglike teeth or forward and backward. The skulls to rigid
were for raking and jaw bones of plant-eating dinosaurs cheekbones.
Camarasaurus
through foliage.
show that some of these animals did the
same. The jaws of Psittacosaurus and Jaw joint
many hadrosaurs could slide forward Plant-eaters
and backward, and ankylosaurs could Jaws
could slide
Iguanodon from side to side, just like sheep. Psittacosaurus forward and
probably chew by moving their jaws
backward.

Iguanodon’s The leaf-shaped teeth
flattened teeth were ideal for snipping
had serrated edges. leaves from the twigs.

Rebbachisaurus

The front teeth were
specialized for cropping
low-growing plants.

The parrotlike beak was
used to gather plant food
and may even have been
used to crack nuts.

Hundreds of teeth Psittacosaurus
formed a complex
grinding surface.

were saw-edged for cutting up leaves, but to spend so much
hadrosaurs such as Edmontosaurus had hundreds of their time eating. As with
of teeth packed together to form a filelike all dinosaurs, the old, damaged
surface, specialized for reducing leaves and other teeth were continuously replaced
plant material to a pulp. This made food much by new ones, so they never
easier to digest, so the hadrosaurs did not need wore out.

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