Ankylosaur Dinosaur Tooth from Montana

Description: Euoplocephalus (meaning well armored head) was an astonishing looking large armored dinosaur. This three to five ton, up to 20 foot long, behemoths’ body was covered in an array of large sharp spikes to ward off predators like T-Rex. In this it was quite successful and thrived in the late Cretaceous until the great Cretaceous-Tiertiary Extinction Event that doomed all the large dinosaurs. Fossils of Euoplocephalus are known from Alberta, Canada and Montana in the United States, including one almost complete skeleton found with its armor still attached.

Ankylosauria contains two families, Nodosauridae (the nodosaurids) and Ankylosauridae (the ankylosaurids). Most ankylosaurids (except the "polacanthines") have bony clubs at the end of their tails, while the nodosaurids do not. They are first known from the early Jurassic Period of China. They have been discovered on every continent except Africa.