KidZone Animals: Dinosaurs
Dermal Armour Dinosaurs
One group of dinosaurs is called thyreophorans, which means "shield bearers". All of the dinosaurs belonging to these groups have dermal armour. Dermal armour are pieces of bone that are embedded in the skin. The bones of the dermal armour are not actualy attached to the skeleton of the dinosaur but come straight out of the skin.
Depending on the dinosaur, the dermal armour might be for different purposes besides defense. Some thyreophorans may use their dermal armour to help recognize members of their species or signify that they are no longer juvenilles.
Thyreophorans are herbivores and but their jaws and teeth were not very well adapted to chewing so they weren't very good of it. They had to spend a lot of time searching for food and chewing to get enough energy to fuel their big dinosaur bodies. Thyreophorans were also relatively low to the ground so the food they ate was to be low to the ground too.
Photographed by Fernando García Redondo;
used with permission under CC BY-NC 2.0
Stegosaurus are a very well known dermal armour dinosaur. They have two parellel rows of plates that follow their spine and then become two parellel rows of spikes that follow their tails. Since their dermal armour didn't protect their sides, stegosaurus likely used their plates and spikes for species recognition instead of protection and defense. There is also evidence that stegosaurus were not particularly intelligent dinosaurs because their brains were very small compared to their bodies and mostly devoted to smelling.
Ankylosaurus are another well know dermal armour dinosaur. They had bones all around their bodies and clubs on the end of their tails. Since they were so well equipped with dermal armour, ankylosaurus likely used their armour for protection from predators. As long as their bellies weren't exposed and they had room to swing their tails, ankylosaurus were very safe.