Stegosaurs were four legged, plant eating dinosaurs. This group of dinosaur, which first appeared in the early Jurassic period and gradually faded away in the early Cretaceous era, were as long as 9 metres. They came from various parts of the planet and depending on the region they differed slightly in size and structure. The most striking feature of these dinosaurs were their spiky plates lined along the neck, back and tail.
‘Roof lizards’, the Stegosaurs, are said to have first appeared in China, with the Tuojiangosaurus, however by the end of the Jurassic period the group included also the Kentrosaurus from East Africa, the Lexovisaurus from Europe and finally the Stegosaurus from North Africa. The Stegosaurus was the largest of the group, which grew to lengths of 30 foot and could be compared to the size of a bus.
The first fossils of this dinosaur were found in the western part of the United States. Since its discovery scientists have disagreed about the exact purpose and arrangement of the plates that existed along the dinosaurs back. The first theory was that they served as a form of protection, however this is unlikely as the plates were thin and lined with blood vessels, which were most likely covered with skin as opposed to bone.
The other theory is temperature control, where the plates served as radiators, helping the Stegosaurs keep warm when they turned toward the sun and cool down when they turned away. However Stegosaurs did have a form of protection, they were equipped with a mace like tail, which was made up of at least two long pairs of sharp, bony spikes, covered in horn.
The Stegosaurs dwelled mostly in open woodland, where they had access to plenty of plants, which would have had to be consumed in huge amounts to maintain their great huge mass. Like the spiky plates on the Stegosaurs, the brain of the dinosaur also created some debate. It is believed that the Stegosaur has two brains, one small brain in the skull and a larger brain located near the hip. Despite the brain in the skull being no larger than a walnut, scientists discovered that this brain was its primary brain that controlled the body, however the other brain only held nerves and controlled the hind limbs and tail, whilst possibly storing glycogen for powering muscles.