This section is taken from the Dinosaur Field Guide.
Edmontonia ("Lizard from Edmonton [Canada]") is a nodosaur, a kind of ankylosaur without a tail club. It had two large spikes on each shoulder that pointed out to the side. These spikes were a great defence against predators because they were at the same level as the knee and calf muscles of a larger theropod or predator. If attacked, this slow-moving tank would throw its weight behind these spikes and drive them into the predators legs. This would immediately disable the attacker and allow Edmontonia to walk away.
Although the skull of Edmontonia was long and shallow, it had room for four sinus cavities. This meant the skull was lighter, and probably improved the dinosaur's sense of smell. Edmontonia's teeth were amazingly small for such a large animal. One tooth was only half an inch (1 cm) long and barely a fifth of an inch (5 mm) wide - far too small for eating most plants. Did Edmontonia also eat ants and insects, like the modern anteater? Or were its teeth disappearing over time because its beak did all the work? These are mysteries that Palaeontologists have yet to solve!
Jurassic Park Franchise
Edmontonia does not appear in the movies or novels, although it did appear in one video game.
Edmontia appears in the booklet of the Jurassic Park: DNA case.