Ankylosaurus was an armored dinosaur known for its distinctive appearance. This large herbivore had heavy body armor, composed of bony plates called osteoderms embedded in its skin. Its most recognized feature was a massive, club-shaped tail, which served as a formidable defensive weapon. Its robust build and low stature were characteristic.
A Look Back in Time
Ankylosaurus lived during the Late Cretaceous Period, approximately 68 to 66 million years ago, making it one of the last non-avian dinosaurs before a major extinction event. During this era, Earth experienced a warmer and more humid climate, with little to no ice at the poles. Shallow inland seas covered large portions of continents, including North America. Terrestrial ecosystems were dominated by diverse dinosaur groups.
Their Ancient World
Ankylosaurus inhabited western North America, a region that now encompasses parts of Canada and the United States. Fossil evidence indicates its presence in areas like Alberta and Saskatchewan in Canada, and Montana, Wyoming, and South Dakota in the U.S. This landmass, known as Laramidia, was separated from eastern North America by the Western Interior Seaway. Ankylosaurus thrived in warm, humid environments, including temperate to subtropical forests, floodplains, and deltas.
The vegetation in these habitats was abundant, providing ample food. Dominant plant forms included conifers, ferns, cycads, and an increasing variety of flowering plants (angiosperms). Ankylosaurus, with its broad muzzle and leaf-shaped teeth, was a non-selective browser, feeding on low-lying plants and foliage close to the ground. Its specialized diet and physical adaptations allowed it to thrive.
Unearthing the Past
Scientists reconstruct the ancient world of Ankylosaurus through fossil evidence and paleoenvironmental analysis. Ankylosaurus fossils have been discovered in geological formations, providing direct clues about its former range and surroundings. Key sites include the Hell Creek Formation in Montana, the Lance Formation in Wyoming, and the Scollard Formation in Alberta, Canada. These formations represent ancient coastal floodplains, swamps, and low-land forests, reflecting the environments where Ankylosaurus lived and died.
The geological context of these fossil sites is important, offering insights into the end of the dinosaur era. Paleoenvironmental analysis, which examines sediments, plant fossils, and other co-occurring animal remains, helps paleontologists understand the climate and ecosystem of the time. The rare nature of complete Ankylosaurus skeletons means understanding relies on fragmentary remains and comparisons with related armored dinosaurs.