Amargasaurus was one of the smallest sauropod dinosaurs at just 33 feet (its relatives could reach 140 feet!!). It had a quadrupedal stance. Using its neck, it could feed on plants low to the ground and up in trees. Its most notable features were tall spines along its neck. These spines were for display to fellow Amargasaurus, much like those seen on today’s reptiles. It is unclear if there was skin between the spines; this remains a topic of debate among paleontologists. Like most dinosaurs, Amargasaurus is know from a single specimen discovered in Argentina.
Reference: text is from the park placard with minor edits.