Ankylosaurus

Ankylosaurus is a genus of herbivorous armored dinosaurs from the Late Cretaceous period, belonging to the family Ankylosauridae. The best-known species is Ankylosaurus magniventris, and the genus is characterized by a broad, low-slung body and extensive dermal armor. Ankylosaurus lived roughly 68 to 66 million years ago in what is now North America, with fossils primarily found in western North American formations such as the Hell Creek and nearby beds.

Physically, Ankylosaurus had a wide, squat frame and a broad skull equipped with a beak and rows of leaf-shaped teeth suitable for processing low vegetation. Its back was covered with thick, interlocking armor plates (osteoderms) and capable of bearing spikes and knobs. A distinctive feature was the large bony club at the end of its tail, formed by fused tail vertebrae and osteoderms, which researchers believe was used as a powerful defensive weapon against predators.

Paleobiology and behavior are inferred from its anatomy: Ankylosaurus was likely slow-moving and low-browsing, feeding on ground-level plants. Its heavy armor and tail club suggest a defense strategy against large theropods such as Tyrannosaurus rex. The discovery of well-preserved specimens has made Ankylosaurus one of the most recognizable and studied armored dinosaurs, illustrating the diversity of defense adaptations among ornithischian dinosaurs.

Discovery and classification: Ankylosaurus magniventris was formally described in 1908 by Barnum Brown. The genus name means “fused lizard,” referring to its fused armor elements.