Armargasaurus was a sauropod from South America during the early cretaceous period. It lived in large herds and was a herbivore that ate mid level leaves. It was not a big sauropod compared to other sauropods but it had a sail on its back that can look intimdating larger predators. Other uses for the sail was to attract other mates of the same species. There are many other hypothesis around the Armargasaurus sail from that the sail could help to regulate its body temperature like the Spinosaurus and Diemetrodon Sails. But here I will use the two major theroys that most likely be true.