Why were ankylosaurs usually a match for predators?

                                   Ankylosaurs such as Euoplocephalus had heavily armoured backs, like a military tank. However, they did not rely only on this to protect them from attack. A huge club of bone grew on the end of its tail, and the Euoplocephalus could use it as a fearsome weapon if attacked. Meat-eating dinosaurs walked on two legs, so they would have been very vulnerable to a blow from the club on the tip of an ankylosaur’s tail. Such a blow would easily have shattered a leg and left the animal helpless. Other ankylosaurs such as Edmontonia were not only heavily armoured, but they had long shoulder spikes facing forwards.  These spikes would have caused very deep wounds if the ankylosaur lunged at its attacker.

When was it a good defence to lie down?

                             For many ankylosaurs, some of which had no tail club, lying down prevented the predator from reaching its soft underparts. In many of these animals, such as Sauropelta and Hylaeosarus, the sides of the body were edged with heavy spikes. A predator would have found it very uncomfortable to try and turn its prey over. The interlocking bony plates on the ankylosaurs’ back meant that there were no gaps in its armour. Even if it was tipped over, an ankylosaur called Minmi had armour underneath its body to protect its soft belly.

Picture credit: google