Argentinosaurus

What it was like

Argentinosaurus was a giant among giants, a long-necked plant eater that ranks among the largest land animals ever known. Estimates put it at around 35 meters long and about 70 metric tons in weight, supported by thick, pillar-like legs and a long tail that balanced its equally long neck.

Only a small part of its skeleton has ever been found, including huge back bones and a massive thigh bone, so much of what scientists know about its full size comes from comparing these bones with more complete relatives. Its sheer bulk would have made a full-grown Argentinosaurus nearly impossible for most predators to bring down.

Its world

Argentinosaurus lived in the Early Cretaceous, from about 110 to 106 million years ago, in what is now Argentina. Its remains were found in the Huincul formation, a rock layer that has also produced the giant predator Giganotosaurus.

Sharing a landscape with such a large hunter, Argentinosaurus likely relied on its size alone for protection once fully grown, since few predators of the time could have threatened an animal so large. Other animals from the same formation include Mapusaurus and the smaller Limaysaurus.

How it was found

Argentinosaurus was named by Bonaparte and Coria in 1993, based on fossils found in Argentina. Only one find of the genus has been recorded, which is why its exact size is still debated, with estimates sometimes revised as scientists compare it with better-known relatives such as Patagotitan and Dreadnoughtus.