Mapusaurus, meaning “earth lizard”, is a genus of carnosaurian dinosaur from the Late Cretaceous Period and lived in what is now Argentina. Its remains were discovered in a fossil bed containing at least seven individuals of different life stages. This finding has led some scientists to speculate that Mapusaurus hunted in groups together to take down large prey. If this speculation holds any truth, then it would be the first substantial evidence of gregarious behavior in large theropods other than Tyrannosaurus. It is unknown if they may have hunted as a sophisticated pack, such as wolves do today, or if they simply attacked as a mob of hungry predators.
This theropod was about 40 feet in length and weighed over 3 tons. It was excavated from 1997 to 2001 in the Huincul Formation at Canadon de Gato. It was named and described by paleontologists
Rodolfo Coria and Phil Currie in 2006. Mapusaurus got its name from the Mapuche word Mapu, which means “˜of the land’. The species, M. roseae, was named for both the rose-colored rocks where it was found, and for Rose Letwin, who sponsored the expedition to recover the specimen.

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