Mapusaurus, a large carnivorous dinosaur from the Late Cretaceous period, was discovered in the late 1990s in the Huincul Formation of Patagonia, Argentina, Mapusaurus represents one of the largest theropod dinosaurs ever found. Belonging to the Carcharodontosauridae family, it is closely related to other giant predators like Giganotosaurus and Carcharodontosaurus.

Mapusaurus was a massive predator, estimated to have reached lengths of up to 40-43 feet (12-13 meters) and weighing several tons. Its robust build, powerful limbs, and sharp teeth indicated its status as an apex predator in its ecosystem. Its skull featured a series of serrated teeth that would have been formidable tools for hunting and consuming large prey.

The presence of multiple Mapusaurus fossils found together in the same rock layer raises the possibility of pack hunting behavior. This hypothesis is supported by the size range and developmental stages of the individuals, indicating that different members of the pack may have specialized roles in hunting or scavenging.

Mapusaurus has been identified through distinctive characteristics in specific parts of its skeleton, which are not preserved in its relative, the Giganotosaurus, leading to its diagnosis based on autapomorphies. The only contrasts between Mapusaurus and Giganotosaurus lie in the absence of a secondary opening on the middle quadrate and certain nuances in the arrangement of the nasal rugosities.