世界共通発音：ステゴソーラス steg oh saw rus
分類所属：Ornithischia / Genasauria / Thyreophoroidea / Eurypoda / Stegosauria /
Family: Stegosauridae /
FIRST DESCRIBED: 1877 / FOUND: North America: USA; Africa: Madagascar / LENGTH: 9 m
/ WEIGHT 2.5 t / FOOD: Plants / YOUNG: Eggs
/ LIVED: Late Jurassic 154 146 million years ago
If there was a prize for the most famous dinosaur, then Stegosaurus and Tyrannosaurus (see page 64) would be the two main contenders. They are totally different animals but both have excited our imaginations. Stegosaurus was a placid plant eater with an exceptionally small brain. It had a long, flattened head with a beaked mouth. The jaw teeth were small and probably rubbed against one another like grindstones as the animal chewed its food before swallowing.
Stegosaurus was the largest of the stegosaur dinosaurs. It is easily recognized by the two rows of vertical plates along its back and the four huge spikes on its tail. What could Stegosaurus's plates have been for? They are slightly off set and inside there are recognizable channels that probably filled with blood. They may have acted like radiators. Alternatively, they may have been used for display between males and females. They would not have been much use for protecting the animal during an attack. For this, Stegosaurus relied on its four spiked tail. Each spike was about 1 m long, and could have inflicted terrible wounds on the legs and underbelly of its tormentor.