Ankylosaurus, a heavily armored dinosaur, roamed western North America during the Late Cretaceous period, approximately 68 to 66 million years ago. This quadrupedal creature, known for its distinctive bony plates and powerful tail club, reached lengths between 20 and 26 feet and weighed up to 8.8 tons.
A Definitive Answer: Yes, It Was a Herbivore
Ankylosaurus was a herbivore. Evidence lies in its oral anatomy, which included a beak at the front of its jaws. Behind the beak were rows of small, leaf-shaped teeth, compressed sideways. These teeth were designed for stripping and cropping soft plant material.
The Ankylosaurus jaw structure indicates a grinding motion, suitable for processing vegetation. Unlike the blade-like, serrated teeth of carnivores, Ankylosaurus possessed teeth adapted for plants. Available skull and dental fossils provide indicators of its herbivorous nature.
What the Ankylosaurus Ate
The Ankylosaurus’s low-slung body and broad muzzle were well-suited for consuming low-growing vegetation. It grazed on ground cover, including ferns, cycads, and low-lying shrubs. Its small, leaf-shaped teeth limited its diet to softer foliage and potentially pulpy fruits, as it could not efficiently process tough, fibrous plants or bark.
Paleontologists estimate an Ankylosaurus needed to consume around 60 kilograms (approximately 130 pounds) of plant matter daily to sustain its massive size, a quantity comparable to a modern elephant. This suggests a non-selective browsing habit, feeding on readily available soft vegetation. Fossilized plant remains in the same geological layers as Ankylosaurus fossils further support the identification of its food sources.
Anatomical Adaptations for a Plant-Based Diet
Other anatomical features also supported its herbivorous lifestyle. Its broad snout, wider than long, aided in gathering large quantities of vegetation. The dinosaur’s large body housed a sizable digestive system, crucial for breaking down plant cellulose through fermentation. This digestive process is common in modern large herbivores.
The heavy armor and tail club, while serving as defensive mechanisms against predators like Tyrannosaurus rex, also supported its feeding strategy. Its robust protection allowed Ankylosaurus to graze safely for extended periods without constant threat. This ability to forage undisturbed for long durations was essential for processing the large volume of plant matter required to sustain its substantial body mass. These combined physical attributes underscore Ankylosaurus’s role as a plant-eater.