Giganotosaurus is a genus of Carcharodontosaurid dinosaur that lived 100 to 95 million years ago during the Cenomanian and the Turonian stages of the Mid Cretaceous Period. It is one of the largest known terrestrial carnivores. its fossils have been found in Argentina. It was very similar to Jurassic giant Allosaurus, however this creature was slightly bigger and stronger. Giganotosaurus was larger than T. rex, but had a brain only about half as big as those of tyrannosaurids.
Giganotosaurus was 40 to 46 feet long (12-14 meters) and weigh roughly 6 to 8 tonnes. The teeth of Tyrannosaurus were longer and wider, but more variable in size. The teeth of Giganotosaurus were shorter, less variable and narrower than those of Tyrannosaurus, and were more adapted for slicing flesh as to a blade or knife. A well-developed olfactory region means that it probably had a good sense of smell. Its skull, although large, had a slender build. It´s arms were long and powerful, tipped with large claws on each toe, that were used to open huge gashes onto the flesh of it´s prey.
Titanosaur fossils have been recovered near the remains of Giganotosaurus, leading to speculation that these carnivores may have preyed on the giant herbivores. Fossils of related carcharodontosaurids grouped closely together may indicate pack hunting, a behavior that could possibly extend to Giganotosaurus itself. Blanco and Mazzetta (2001) estimated that Giganotosaurus might have been capable of running at speeds up to 14 metres per second (31 mph).