Amargasaurus lived during the early Cretaceous Period, from about 131 to 125 million years ago.Amargasaurus is known from am almost complete skeleton (it is missing the front of the skull and the tail). Amargasaurus was found in La Amarga, a canyon in Argentina. It was name by paleontologists Salgado & José Bonaparte in 1991.Amargasaurus was a large herbivorous dinosaur, a saurischian ("lizard hipped" dinosaur), a sauropodomorph (long-necked, long-tailed plant-eater who walked on four legs), a sauropod (very large herbivore), and a member of the family Diplodocidae (peg-toothed sauropods, which included Apatosaurus, Supersaurus, Seismosaurus, Diplodocus, and others). Amargasaurus is very similar to Dicraeosaurus.