Period of life:
Stegosaurus is the largest member in the Stegosauria suborder of the Ornithischian order. It lived in the Jurassic period about 155-145 million years ago. Its name means in Latin "roof(ed) lizard". Indeed, thanks to the sharp plates stuck along the entire back it looked like a tiled roof.
Stegosaurus had up to 4 tonnes weight, height up to 4 metres and its body length could reach 9 metres. The reptile had a very tiny head for that body size. It was only 35 cm long, smaller than a living horse with a tiny walnut size brain. Even Diplodocus had a chicken egg sized brain for its 1-metre head.
The dinosaur feed was purely floral. It snapped the plants with a horny beak. The jaws in front of the beak allowed reptile chewing only soft foliage. The massive body required vast feed amount, so the Stegosaurus consumed monstrous rations of food. Thus, Stegosaurus swallowed medium size stones to help rough foliage grinding in the gut. This feature was common for many herbivorous dinosaurs.
The reptile moved on mammoth hind limbs and much smaller forelimbs. Because of the tiny forelimbs, its back was curved in a large hump. Distinctive feature that set Stegosaurus apart from other dinosaurs was its picturesque back plates. Diamond shaped plates stretched in two twisted rows. A tail tip and neck both got four bone spikes. The scientists believe those spikes were barely used for protection because of its fragility. Large predators could easily snap those spikes off.
How did the Stegosaurus defend itself? It turns out that Stegosaurus vascular system spread into the back plates as well. Tiny blood vessels made the plates turn red when an attacker approached. As a red colour always means danger or warning all predators hesitated and might have even abandoned an ambush.
The plates also served for frost protection as it could work like a solar power station for sunlight absorbing and heat exchange. The plates were very multi-purposed and used in the mating rituals as rivalry with other males.