Ankylosaurus was a dinosaur that evolved a mass of bone at the end of its tail it was used to smash the legs of predators during a fight. Even the t-rex was wary of this strange dinosaur.
"Ankylosaurus was a bulky, armored herbivore from the late Cretaceous period with a large clubbed tail that could shatter predator's bones."
Tail Club (Speed Path)
"A new development that helped herbivores protect themselves, the bony clubbed trail could fend off even large predators."
Ossification (Payout Path)
"Many bones throughout the Ankylosaurus' skull and body were fused, which greatly increased their strength and durability. Their name is derived from the medical term ankylosis: the process of fusing bones."
Ankylosaurus is a genus of armored dinosaur. Its fossils have been found in geological formations dating to the very end of the Cretaceous Period, about 68–66 million years ago, in western North America, making it among the last of the non-avian dinosaurs. It was named by Barnum Brown in 1908; the only species in the genus is A. magniventris. The genus name means "fused lizard", and the specific name means "great belly". A handful of specimens have been excavated to date, but a complete skeleton has not been discovered. Though other members of Ankylosauria are represented by more extensive fossil material, Ankylosaurus is often considered the archetypal member of its group, despite having some unusual features.