Ankylosaurus Dinosaur Coloring Page & Printable PDF

Ankylosaurus Dinosaur: History & Fun Facts

Ankylosaurus lived in what is now western North America near the very end of the Cretaceous period, about 68 to 66 million years ago, making it one of the last non-bird dinosaurs before the mass extinction. It grew to roughly 20 to 22 feet long and could weigh 6 tons or more, low and wide like a loaded army truck rather than tall like many of its plant-eating relatives.

A Body Covered in Bony Armor

Thick oval plates called osteoderms studded its back, neck, and sides, some fused directly into the skin so tightly that early scientists named the animal "fused lizard." Smaller nodules of bone filled the gaps between the larger plates, and even its eyelids had bony covers that could snap shut for protection. Few animals in Earth's history carried that much personal armor at once.

The Signature Tail Club

At the end of its tail, several vertebrae fused together to anchor two large knobs of bone, forming a solid club roughly the size of a large bowling ball. Muscle studies suggest a full swing could deliver enough force to fracture bone, likely aimed low at the ankles and shins of an attacking Tyrannosaurus rex, which shared the same landscape and time period.

A Low Grazer With a Wide Beak

A broad, toothless beak at the front of the jaw let Ankylosaurus crop ferns, horsetails, and other low plants close to the ground, while small leaf-shaped teeth further back did light chewing. Its wide-set legs and barrel-shaped ribcage kept its center of gravity low, making it hard for a predator to flip over even with the armor as an obstacle.

Discovery in Montana and Alberta

Barnum Brown, working for the American Museum of Natural History, described the first Ankylosaurus remains in 1908 from a partial skull and skeleton found in Montana's Hell Creek Formation. Complete tail clubs are rare finds even now, since the fused bone often separated from the rest of the skeleton after death, which is part of why paleontologists still debate exactly how the animal used that weapon.

Only a handful of Ankylosaurus specimens have ever been recovered, which is unusual given how large and heavily armored the animal was. Its scattered plates tend to separate from the skeleton quickly after death, so most museum mounts combine bones from more than one individual to show the complete animal.

Sharing Hell Creek With T. Rex

Ankylosaurus shared its home range with Tyrannosaurus rex and Triceratops, making it one of the last large plant-eaters to face the era's biggest predators before the asteroid impact that ended the Cretaceous. Its heavy armor and clubbed tail suggest it was built specifically to survive encounters that a lighter, unarmored herbivore could not.

Coloring a Living Tank

The outline breaks the armor into distinct plates across the back and a clear round club at the tip of the tail, giving kids an easy way to pick out separate colors for the bony sections versus the softer belly underneath. Younger children can fill the wide body in one solid shade, while older kids can pick out individual osteoderms in alternating tones for a scaled, tank-like finish.