Ankylosaurus

Ankylosaurus Temporal range: Upper Cretaceous 68 - 65 mya
Cast of Ankylosaurus skull (AMNH 5214) in front view, Museum of the Rockies
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	†Ornithischia
Clade:	†Thyreophora
Suborder:	†Ankylosauria
Family:	†Ankylosauridae
Tribe:	†Ankylosaurini
Genus:	†Ankylosaurus Brown, 1908
Species:	†A. magniventris
Binomial name
Ankylosaurus magniventris Brown, 1908

Tail club of Ankylosaurus

Skull (AMNH 5214) from the side and above

Replica of the 1964 World's Fair Ankylosaurus (note spikes and dragging tail), Royal Alberta Museum

Ankylosaurus magniventris was a type of armored dinosaur. It was the largest of its type, with a maximum length of 8 m (26 ft) and height of 2 m (6.6 ft).

The body was broad and low-slung and covered in armor. Carnivores, attacking from above, would find no weak points, and the animal could defend itself by using its clubbed tail.

Ankylosaurus was a herbivore, like all ankylosaurs. It probably ate ferns and cycads, which were common low-growing plants.

Armor

The most obvious feature of Ankylosaurus is its armour, consisting of massive knobs and plates of bone, known as osteoderm or bony scutes, embedded in the skin. Osteoderms are also found in the skin of crocodiles, armadillos and some lizards. The bone was probably overlain by a tough, horny layer of keratin.

These osteoderms ranged greatly in size, from wide, flat plates to small, round nodules. The plates were aligned in regular horizontal rows down the animal's neck, back, and hips, with the many smaller nodules protecting the areas between the large plates. Smaller plates may have been arranged on the limbs and tail. Compared to the slightly more ancient ankylosaurid Euoplocephalus, the plates of Ankylosaurus were smooth in texture, without the high keels found on the armor of the contemporaneous nodosaurid Edmontonia. A row of flat, triangular spikes may have protruded laterally along each side of the tail. Tough, rounded scales protected the top of the skull, while four large pyramidal horns projected outwards from its rear corners.

Underneath it was covered by normal skin, but to get at it the carnivore would have to turn over an animal weighing up to 4 t (4,000 kg).

In movies

Ankylosaurus features in the Jurassic Park series of movies. In Jurassic World: Fallen Kingdom, several Ankylosaurus flee from a volcanic eruption and at least one is captured by mercenaries. It was later auctioned off to a wealthy Indonesian.