Argentinosaurus huinculensis is a basal titanosaur from the Lognkosauria family. In contention for the largest dinosaur (with Dreadnoughtus and Patagotitan), it is a sauropod, a large quadruped with a long tail and long neck, estimated to be be between 22 and 40 metres (72 to 131 feet) in length.
Argentinosaurus lived in the Late Cretaceous plains of what is now central Argentina. Titanosaurs include the largest sauropods ever discovered, and were also the last surviving sauropods at the end of the Cretaceous. Being so large, it is thought that the only possible predator of Argentinosaurus was Giganotosaurus, the largest known theropod.
The holotype has no skull, but consists of multiple vertebrae and ribs, and some leg bones. It was discovered by Guillermo Heredia on his ranch in Northwestern Río Negro province in 1987. Due to the only specimen being rather incomplete, the size of Argentinosaurus can only be estimated by comparison to other titanosaurs, and has varied over the years.
"Argentinosaurus" refers to the country the dinosaur was discovered in, Argentina. "Huinculensis" is in reference to the Huincul Formation, where the fossils were discovered.