Which dinosaur had a bony club at the end of its tail?

The dinosaur with a bony club at the end of its tail was Ankylosaurus.

Ankylosaurus was a heavily armored, four-legged herbivore that lived during the Late Cretaceous. Its tail club consisted of enlarged osteoderms—bony plates embedded in the skin—supported by a stiffened section of tail vertebrae. The reinforced tail could be swung sideways and may have served as a powerful defensive weapon.

Fossils of Ankylosaurus have been found in western North America, including rocks of the Hell Creek Formation. The genus was named in 1908, but the first known Ankylosaurus tail club was discovered during an American Museum of Natural History expedition in 1910. The club helped make the dinosaur one of the most recognizable armored dinosaurs.

Ankylosaurus is often confused with Stegosaurus because both were armored herbivores associated with dramatic tail structures. Stegosaurus had a row of pointed tail spikes, called a thagomizer, rather than a single bony club. Other ankylosaurids also possessed tail clubs, but Ankylosaurus is the classic quiz answer.