Ankylosaurus is a genus of Ankylosaurid Dinosaur, that lived to the very end of the Cretaceous 70-66 Ma ago in western North America. It was 6-8 meters long, 1.80 metres tall and approximately 6-7 tons in weight with heavy armour. It was a herbivorous Dinosaur that had very limited intelligence due to its skull being heavily reinforced (as was the rest of the animal) with armour, leaving little space for much of a brain at all. It would most likely have been reduced to instinctive reactions though it may have been able to learn from experience, that made it appear a rather unpredictable and aggressive Dinosaur.
Palaeontologists and Dinosaur fans alike often informally refer to this as the 'Battle Tank of Dinosaurs', the bane of Tyrannosaurus rex.
Ankylosaurus was featured in the final episode of Walking with Dinosaurs, Episode 6: Death of Dynasty. This event is shown, shortly after Ankylosaurus successfully fights the mother Tyrannosaurus rex, inflicting enough massive damage to kill it. In the later sequel, Walking with Beasts, this scene was re-shown as a prequel to the first episode of those series.