| Named By: | Friedrich von Huene in 1929 |
| Time Period: | Late Cretaceous, 83 Ma |
| Location: | Argentina, possibly Brazil |
| Size: | Uncertain due to incomplete and uncertainty of attributable remains. Lower estimates however have suggested a size of around 18 meters long for the type species, while other material indicates an upper size of up to 30 meters long if the classification is correct. Refer to main text for details |
| Diet: | Herbivore |
| Fossil(s): | Several remains but of incomplete individuals and scattered bones |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Sauropodomorpha | Sauropoda | Titanosauria | Antarctosauridae | |
Antarctosaurus (meaning "southern lizard") is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. The type species, A. wichmannianus, was described by prolific German paleontologist Friedrich von Huene in 1929, who also described a second species in 1929. Three additional species of Antarctosaurus have been named since then. Later studies indicate that none of these pertain to Antarctosaurus.
Antarctosaurus was very large, even for a sauropod. Scientists still have much to learn about Antarctosaurus, as a complete skeleton remains elusive.