Ankylosaurus magniventris ang-KIE-loh-SOR-us
"Fused lizard"
You 1.8 m (5.9 ft) tall
Ankylosaurus 7 m (23 ft) long
4 people holding hands
- Length
- 7 m (23 ft) — About 7 m long, ~4 tonnes — a living tank with a club-tipped tail.
- Period
- Late Cretaceous (68–66 Mya)
- Place
- North America · Western United States · Alberta, Canada
- Food
- Herbivore — Low-growing tough plants — the wide gut housed bacteria that broke down fibrous material.
Ankylosaurus was a heavily armored herbivore that lived alongside Tyrannosaurus rex right up until the asteroid impact. Bony plates covered its body from the eyes to the tip of the tail, and the tail ended in a huge bony club that could swing with enough force to break the leg of a T. rex.
What we know
- Body almost completely covered by armor — even the eyelids were bony.
- Tail ended in a fused mass of bone — a club weighing around 30 kg.
- Lived alongside T. rex, Triceratops, and Edmontosaurus in the final million years of the Cretaceous.
- Wide barrel-shaped body to house a long fermenting digestive tract.
What we guess
- Tail club swing speed and force — biomechanical models suggest enough to fracture bone.
- Whether it could outright defeat a T. rex or just discourage attack.
- Whether it lived in herds or solo, since most specimens are isolated.