The late Cretaceous Period, about 70-65 million years ago
North America: The western USA (Montana) and Canada (Alberta), and Near Sucre, Bolivia, South America
The last and largest of the tank-like armored dinosaurs, Ankylosaurus (meaning “Fused reptile”) was well protected from big meat eaters. Large bony plates, which probably had additional horn-like coverings, protected its flanks. The skull was thick with two pairs of sharp horns at the back of the head. Parts of the tail vertebrae were fused like the handle of a club, while the base of the tail remained flexible. The end of the tail was a large bony club which would have been a devastating defensive weapon wielded against attacking predators. Analysis of Ankylosaurus’s brain cavity indicates the most highly developed part of its brain was devoted to its sense of smell.