Argyrosaurus (/ˌɑːrdʒaɪroʊˈsɔːrəs/ AR-jy-roh-SOR-əs) is a genus of titanosaurian sauropod dinosaur that lived about 70 million years ago, during the Late Cretaceous Period of what is now Argentina.

[7][4] In 1979 Bonaparte and Gasparini referred a partial skeleton, PLV 4628/MACN-CH 217, which included limb material and several vertebrae from Chubut Province to Argyrosaurus.

Many of the referred specimens either have no overlapping material, lack key features in the holotype, or were not illustrated making not possible to assign them without being restudied.

They also considered one of the referred specimens, the partial skeleton PLV 4628/MACN-CH 217, to be its own genus which they called Elaltitan.

[10] However, in 2012 Thomas Holtz gave a higher estimation at 28 metres (92 ft) in length and a possible weight of 43.5-50.8 tonnes (48-56 short tons).