Argentinosaurus

Lore & Background

Additional specimens include a complete femur and the shaft of another. The fragmentary nature of Argentinosaurus remains makes their interpretation difficult. Arguments revolve around the position of the recovered vertebrae within the vertebral column and the presence of accessory articulations between the vertebrae that would have strengthened the spine. A computer model of the skeleton and muscles estimated this dinosaur had a maximum speed of 7.2 km/h (5 mph) with a pace. The fossils were recovered from the Huincul Formation, which was deposited in the Albian stage and contains a diverse dinosaur fauna, including the giant theropod Mapusaurus.

Reader's Guide

Argentinosaurus is significant as one of the largest known land animals, though its exact size is debated due to fragmentary remains. Estimates of its length range from 30 to 39.7 meters, and mass estimates vary from 60 to 100 tonnes, with later studies converging around 65–80 tonnes. It represents the titanosaurian sauropods that dominated the Cretaceous. The discovery and naming by Argentine paleontologists highlight the rich fossil record of South America. The Huincul Formation, where it was found, also yielded the giant predator Mapusaurus, suggesting a complex ecosystem. Despite uncertainty over whether it was the largest titanosaur—with contenders like Patagotitan, Puertasaurus, and Futalognkosaurus—Argentinosaurus remains a benchmark for giant sauropod size. Its fragmentary nature underscores the challenges in reconstructing extinct giants.

Did You Know?

• A computer model estimated Argentinosaurus had a maximum speed of 7.2 km/h (5 mph) using a pace gait.
• The species name huinculensis refers to the town Plaza Huincul, near where the fossils were found.
• The fossils were recovered from the Huincul Formation, which also contains the giant theropod Mapusaurus.