 Amargasaurus was discovered in sedimentary rocks of the La Amarga Formation, which dates back to the Barremian and late Aptian of the Early Cretaceous epoch. It shared its environment with at least three other sauropod genera, which might have exploited different food sources in order to reduce competition. Amargasaurus probably fed at mid-height, as shown by the orientation of its inner ear and the articulation of its neck vertebrae, which suggest a habitual position of the snout some 80 centimeters (31 inches) above the ground and a maximum height of 2.7 meters (8.9 feet). Within the Sauropoda, Amargasaurus is closely related to the Late Jurassic genera Dicraeosaurus, Brachytrachelopan and Suuwassea. Together, these genera form the family Dicraeosauridae, which differ from other sauropods in showing very short necks and small body sizes.
