Quilmesaurus curriei was discovered in the late 1980s by a team led by a field crew led by Dr. Jaime Powell for the Universidad Nacional de Tucumán. It was described in 2001 by Rodolfo A. Coria.
The holotype was discovered within the Allen Formation, in Salitral Ojo de Agua, a body of water near a saltpetre extraction site in the Río Negro province of Argentina. Only one partial specimen has been found, consisting of half a femur and the complete right fibia.
Quilmesaurus is thought to be a Carnotaur from the Abelisauridae family. When originally described in 2001, it was not known what specific family it belonged to, but it was thought not to be a Ceratosaur based on the fact that the tibia wasn't fused with the proximal tarsals (toe bones at the end of the fibia). In 2007, a study was done by Ruben D. Juarez Valieri, Lucas Ernesto Fiorelli, Laura Edith Cruz, and they were able to re-classify Quilmesaurus as an Abelisaurid, possibly a Carnotaur, but they can't be certain with the evidence they have. Abelisaurs are large theropods similar to tyrannosaurs from later in the Cretaceous of South America.
Quilmesaurus curriei's holotype, as stated above, consists of only half a femur and a fibia. In 2016, a study by Orlando Nelson Grillo and Rafael Delcourt was done to re-estimate the sizes of all known Abelisaurids. They concluded that Quilmesaurus was approximately 5.3 metres long.
As with all Abelisaurids, Quilmesaurus is a carnivore. There was no skull found, but it is not likely that Quilmesaurus would be herbivorous.
Quilmesaurus gets its name from the Quilme people, a native group of people native to the area that were known for their ferocity and ability to resist the Incan invaders to their land, and Spanish invaders for 130 years. "Curriei" refers to Phillip J. Currie, a Canadian paleontologist that Rodolfo Coria works with on many occasions.