Stegosaurus (Jurassic)

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 weighedup to 4 tonnes, was up to 4 metres high and its body length could reach 9 metres. The reptile had a very tiny head for the size of the body. 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 diet was purely floral. It snapped the plants with a horny beak. The jaws in front of the beak allowed the reptile to chew only soft foliage. The massive body required vast amount of food, so the Stegosaurus consumed monstrous quantities. Thus, Stegosaurus swallowed medium size stones to help to grind the rough foliage 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. A 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 had 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.