Argentinosaurus huinculensis is a basal titanosaur from the Cenomanian age of the Late Cretaceous. Considered the largest dinosaur ever discovered, 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 was discovered when a rancher called Guillermo Heredia found its shinbone in 1987, and was described in 1993 by José F. Bonaparte and Rodolfo Coria. It was located in the Huincul Formation in the Northwestern part of the province of Río Negro in Argentina.
The holotype consists of some vertebrae, ribs, a fibula, and a partial femur. Gregory S. Paul's reconstruction in the early 1990s estimated the length to be between 25 and 30 metres, and the weight to be between 80 and 100 tonnes. More recent comparisons with other titanosaurs, have put the size estimations at 22-26 metres and the weight around 83.6 tonnes. The holotype (and only specimen) is set up on display at the Museo Carmen Funes in Plaza Huincil, where its assembled length is 39.7 metres, with a height of 7.3 metres. Simulations done in 2013 based off of this reconstruction estimate the movement speed of Argentinosaurus at around 2m/s, or 7km/h. When first described, it was placed in a new family called Andesauridae. Further study, research, and comparisons have placed Argentinosaurus in a number of families, most recently in a family called Lognkosauria.
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 therapod ever discovered.
Argentinosaurus was an herbivore, as with all sauropods. Being the size that it was, and the energy needed to maintain the creature, being a land-based carnivore was just not feasible.
"Argentinosaurs" refers to the country the dinosaur was discovered, Argentina. "Huinculensis" is in reference to the Huincul Formation, where the fossils were discovered.