Like modern herbivores, different dinosaurs had ways of defending themselves. These included: herding together, running away, camouflage and defensive armour, as well the active use of tails, teeth, claws, horns and spikes as weapons. For the giant sauropods, such as Brachiosaurus and Diplodocus, their sheer size would have deterred predators from attacking them, although young or sick individuals would have been vulnerable. Confronted by attackers, the sauropods might have reared up on their hind legs before crashing down on them with their heavy forelimbs and clawed toes. They could also have flicked their whip-like tails with great force into the predators' bodies.

Studies of Stegosaurus's bone structure show how the weapon, sometimes called a "thagomizer", could be used. Unlike many other dinosaurs, the tendons (straps of muscle) in its tail were made of cartilage, not bone. This meant that the tail was flexible: it could be swished from side to side. Stegosaurus's powerful, short forelimbs allowed it to swivel round quickly and launch an attack.

Many fossil Stegosaurus tail spikes found show damage, suggesting they were used in combat. Palaeontologists have even found a punctured bone belonging to an Allosaurus into which a Stegosaurus tail spike fits snugly.

Thumb spike

If attacked by a large, hungry theropod and there was no chance of escape, a cornered Iguanodon had one lethal weapon it could rely on. Up to 15 centimetres (6 inches) long, its thumb spike was strong enough to penetrate a theropod’s thick hide. Iguanodon could rear up on its hindlimbs and jab its spike into its attacker’s neck, eyes or belly.

Tail club

Talarurus was a 5-metre-long (16-foot-long) ankylosaur that lived in Mongolia 98–83 million years ago. Both its back and head were covered by bony plates. Only its belly was soft, forcing an attacker to try and flip this heavy dinosaur on to its back. This was no easy task, especially since Talarurus also carried a huge bony club on the end of its tail. Its ribs and hips were fused together to provide an anchor for the massive swinging muscles in its tail. One blow from the club could cripple a predator so severely it could easily become victim to other predators itself.