The Argentina-Canada Dinosaur Project was initiated in 1997 by the Museo Carmen Funes (Plaza Huincul, Argentina) and the Royal Tyrrell Museum of Palaeontology (Drumheller, Canada). A specimen that was looked at on the very first day in the field turned out to be so significant that it has become the largest dinosaur quarry in Argentina. Initially, it was assumed that there was a single, partial skeleton of a large meat-eating dinosaur called Giganotosaurus. This dinosaur had been described several years earlier on the basis of a skeleton found in the same region in Argentina, and had attracted worldwide notoriety as a meat-eater larger than Tyrannosaurus rex. Subsequent work in the quarry revealed that the new dinosaur is not Giganotosaurus, but is a new type of dinosaur that may even have grown to even larger size. Furthermore, the quarry is a mass-death site, and contains the remains of at least seven individuals of the same species. These range in size from halfgrown juveniles to fully mature adults. The evidence strongly suggests that this was a pack of meat-eaters that probably cooperatively hunted the gigantic sauropod dinosaurs that inhabited South America during the Late Cretaceous.

Ironically, after the pack died in some kind of catastrophe, the bodies were trampled by sauropods. About 30 mi away, another new type of theropod was discovered. This one was not fully grown, but was close to 25 ft long. The skull is very unusual because of its light build and long, elongate snout. There are characters in its skeleton that suggest relationship with some of the theropods of the Northern Hemisphere. Other discoveries include the earliest known bird footprints from South America.