Wikipedia:Today's featured article/October 22, 2017

Amargasaurus was a sauropod dinosaur that lived in what is now Argentina from roughly 129 to 122 million years ago, during the Early Cretaceous epoch. The only known skeleton was discovered in 1984 and is virtually complete. Amargasaurus cazaui, the only species in the genus, was a large animal reaching 9 to 10 m in length, with two parallel rows of tall spines down its neck and back. The spines, taller than in any other known sauropod, probably protruded as solitary structures supporting a keratinous sheath, and may have been used for display, combat, or defense. Alternatively, they might have formed a scaffold supporting a skin sail. A herbivore, Amargasaurus probably fed at mid-height. Discovered in sedimentary rocks of the La Amarga Formation, it is most closely related to the Late Jurassic genera Dicraeosaurus, Brachytrachelopan and Suuwassea. Together, these genera form the family Dicraeosauridae, with shorter necks and smaller body sizes than other sauropods.