At the time when terrible carnivores reigned, herbivores protected themselves from biting thanks to a solid cuirass (armour plate). His name means "rigid lizard". The adults were 19 to 29 feet long and about 6 feet tall and weighed 4 tons. Difficult to bite the Ankylosaur: his back was covered with big quills. Only the belly was his weak point. He had a club-shaped tail, which was very useful. The dinosaur Ankylosaur was a real battle tank on legs. The Ankylosaur and the Triceratops, were one of the last dinosaurs that existed during the extinction of the Cretaceous.