Argyrosaurus is one of the largest known titanosaurs that have ever been found. It lived during the Upper Cretaceous period of what is now Argentina. It stood six meters high at the shoulders and could grow up to (al least) 20 meters! Its weight is estimated at about 30.000 kg! Argyrosaurus was built like a tank with massive forelimbs. It must have been a magnificent animal in adulthood, having very few to no predators.
The holotype of A. superbus has been excavated in 1888 and besides being just the forelimb, the commission of the Museo de La Plata managed to smash the rest of the skeleton, apparently large parts of the body, to pieces during the excavation. Multiple findings have been assigned to this species, but the only remains that are certainly of this species are the ones from the holotype.
Mannion, P. D., & Otero, A. (2012). A reappraisal of the Late Cretaceous Argentinean sauropod dinosaur Argyrosaurus superbus, with a description of a new titanosaur genus. Journal of Vertebrate Paleontology, 32(3), 614-638.