The largest known Tyrannosaurus rex skull measures up to 1.52 meters (5 ft) in length. Large fenestrae
(openings) in the skull reduced weight, as in all carnivorous theropods. In other respects Tyrannosaurus's
skull was significantly different from those of large non-tyrannosaurid theropods. It was extremely wide at
the rear but had a narrow snout, allowing unusually good binocular vision.