Ankylosaurus

# Evolutionary Timeline of Ankylosaurus Ankylosaurus, a heavily armored dinosaur, evolved during the Mesozoic Era as part of the Ankylosauria group. Its evolution was shaped by environmental pressures such as predation from large theropods and changing vegetation in floodplain and forested habitats. Key transitions include the development of body armor and tail clubs for defense. ### Key Milestones: - **Early Jurassic ( ~200 million years ago)**: Emergence of Thyreophora, the armored dinosaur clade, from early ornithischians like Scelidosaurus, driven by the need for protection in predator-rich environments. - **Late Jurassic ( ~150 million years ago)**: Appearance of basal ankylosaurs like Gargoyleosaurus, with initial armor plating evolving in response to theropod threats. - **Early Cretaceous ( ~125 million years ago)**: Diversification of Ankylosauridae, including ancestors with enhanced armor and tail clubs, adapting to diverse ecosystems amid continental shifts. - **Late Cretaceous ( ~68-66 million years ago)**: Peak evolution of Ankylosaurus magniventris, featuring massive body armor and a clubbed tail, thriving in North American floodplains until the K-Pg extinction event.