 Gorgosaurus was smaller than Tyrannosaurus or Tarbosaurus , closer in size to Albertosaurus and Daspletosaurus . Adults reached 8 to 9 m ( 26 to 30 ft ) from snout to tail . Paleontologists have estimated full @-@ grown adults to weigh about 2 @.@ 5 tonnes ( 2 @.@ 8 short tons ) , perhaps approaching 2 @.@ 8 tonnes ( 3 @.@ 1 short tons ) . The largest known skull measures 99 cm ( 39 in ) long , just slightly smaller than that of Daspletosaurus . As in other tyrannosaurids , the skull was large compared to its body size , although chambers within the skull bones and large openings ( fenestrae ) between bones reduced its weight . Albertosaurus and Gorgosaurus share proportionally longer and lower skulls than Daspletosaurus and other tyrannosaurids . The end of the snout was blunt , and the nasal and parietal bones were fused along the midline of the skull , as in all other members of the family . The eye socket was circular rather than oval or keyhole @-@ shaped as in other tyrannosaurid genera . A tall crest rose from the lacrimal bone in front of each eye , similar to Albertosaurus and Daspletosaurus . Differences in the shape of bones surrounding the brain set Gorgosaurus apart from Albertosaurus . 
