A nice article on
Giganotosaurus carolinii - currently the closest rival to Tyrannosaurus rex as far as carnivorous dinosaur body mass is concerned (now that Spinosaurus has been found to weigh a 'mere' 7 tons).
Whenever a new species of enormous theropod is discovered it gets overhyped by the media as being bigger than rex. But every single time this has eventually proven to be not the case (so far).
Acrocanthosaurus, Giganotosaurus, Carcharadontosaurus, Mapusaurus, Tyrannotitan and Spinosaurus.
Rex was heavier than all of the leading contenders (if very slightly shorter than a couple) although it is quite close and I suspect that rex and the others approached the biomechanical limits for a terrestrial predator.
However rex was more heavily built, probably faster, had a relatively huge brain, more advanced binocular vision, bigger teeth and a far more powerful bite when compared to the others.
Still the King (or Queen as the females were probably larger)?
In my eyes - yes.
http://mentalfloss.com/article/59815...giganotosaurus