Ankylosaurus

is a genus of large, heavily armored ankylosaurid dinosaur that lived in western North America during the latest part of the Late Cretaceous Period, approximately 68–66 million years ago. It was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. The genus is known for its extremely robust body, extensive covering of bony armor, broad skull, powerful jaws, and especially its large bony tail club.

The only recognized species is Ankylosaurus magniventris, named by the American paleontologist Barnum Brown in 1908. The generic name Ankylosaurus is derived from Ancient Greek words referring to something "fused" or "bent", alluding to the extensive fusion of bones found in the animal. The specific name magniventris means approximately "great belly", referring to its unusually broad body.

Despite being one of the most recognizable dinosaurs, Ankylosaurus is surprisingly incompletely known. No complete skeleton has yet been discovered, and much of its reconstruction is based on several partial specimens and comparisons with better-preserved relatives.

The first fossils attributed to Ankylosaurus were discovered during expeditions led by Barnum Brown, one of the most prominent American paleontologists of the early twentieth century.

Brown originally discovered material from the Lance Formation of Wyoming in 1906, and additional specimens were collected during subsequent expeditions. In 1908, he formally established the genus Ankylosaurus and described its type species, Ankylosaurus magniventris.

The early reconstruction of the dinosaur was necessarily speculative because the known material represented only parts of the animal. This resulted in some unusual reconstructions that persisted in scientific and popular illustrations for decades.

The limited fossil record also means that some details of the animal's exact proportions remain uncertain.

Discovery and naming

Skeletal Reconstruction

Jiangxi Museum