Species Profile: Ankylosaurus

Ankylosaurus magniventris is a large armored dinosaur known from the Hell Creek formation. It sports armor covering its entire body. Even its eye lids. These animals have large clubbed tails designed to be used as a weapon against large predatory dinosaurs. In the Hell Creek formation, the largest predator Ankylosaurus faced would have been Tyrannosaurus rex. 

The name Ankylosaurus means "Fused-Lizard" and refers to the intense fusion of bone connecting its tail vertebrae to its clubbed weapon at the tails end. Ankylosaurus is but one of many members of a family of dinosaurs called "Thyreophorans" This group of dinosaurs has a rich history in the fossil record and includes much more ancient dinosaurs like Stegosaurus and Scutellosaurus. In the Hell Creek formation however, Ankylosaurus has only one other relative, Denversaurus, a Nodosaur.  Nodosaurs are distinct from Ankylosaurs in that they lack a tail club and instead have shoulder mounted spikes and armor to deter attacks from predatory dinosaurs.