Giganotosaurus carolinii is one of the largest known theropod dinosaurs. Its remains include a well-preserved braincase that displays a suite of derived characters unique to the animal, and others that help establish its relationships amongst the Theropoda. These include the development of a broad frontoparietal skull table that forms a shelf overhanging the supratemporal fenestra, the reorientation of the metotic fissure and fenestra ovalis onto the occiput, the ventral extension of the supraoccipital on either side of the foramen magnum, a broad but low occipital condyle, and pneumatization of the basioccipital. Some characters suggest affinities with South American abelisaurids, but many support a sister grouping of Giganotosaurus and Carcharodontosaurus within a larger group that includes the Asian sinraptorids. The close affinities of Giganotosaurus with the northern African Carcharodontosaurus support the hypothesis of intercontinental connections until mid-Cretaceous times.