Saltasauridae (named after the Salta region of Argentina where they were first found) is a family of armored herbivorous sauropods from the Upper Cretaceous. They are known from fossils found in South America, Asia, North America, and Europe. They are characterized by their vertebrae and feet, which are similar to those of Saltasaurus, the first of the group to be discovered and the source of the name. The last and largest of the group and only one found in North America, Alamosaurus, was in length and one of the last sauropods to go extinct. Most of the saltasaurids were smaller, around in length, and one, Rocasaurus, was only long. Like all sauropods, the saltasaurids were quadrupeds, their necks and tails were held almost parallel to the ground, and their small heads had only tiny, peg-like teeth. They were herbivorous, stripping leaves off of plants and digesting them in their enormous guts. Although large animals, they were smaller than other sauropods of their time, and many possessed distinctive additional defenses in the form of scutes along their backs. Description As sauropods, the Saltasauridae are herbivorous saurischians with the characteristic body plan of a small head, long neck, four erect legs, and a counterbalancing tail. Most sauropods are from the clade Neosauropoda, which is further split into the narrow-toothed Diplodocoidea and the broad-toothed Macronaria. The Macronarians emerged in the Jurassic and a subclade, the Titanosauria, survived into the Cretaceous and spread across the continents. Because of their diversity, wide distribution, and the fragmentary or incomplete nature of most specimens, little is known about the titanosaurs beyond their size and tendency to have scutes. The saltasaurids, one of the several titanosaur families, are recognized by the convexities in certain caudal vertebrae and the markings on their coracoid bones. All saltasaurids have thirty-five or fewer caudal vertebrae, each of which is convex on both sides of its centrum, and the one closest to the tail is shorter than the others. Their coracoid bones have rectangular margins on the anteroventral side, as well as a lip where they meet the infraglenoid. The Opisthocoelicaudiinae, a subfamily of the saltasaurids, are unique in that they lack phalanges in their forelimbs. Although Saltasaurus is known to possess dorsal osteoderms, scutes have not been discovered in all saltasaurids, and it is unclear when and where the evolution of osteoderms occurred in saltasaurids and titanosaurs in general. History of study