 Gorgosaurus lived in a lush floodplain environment along the edge of an inland sea . It was an apex predator , preying upon abundant ceratopsids and hadrosaurs . In some areas , Gorgosaurus coexisted with another tyrannosaurid , Daspletosaurus . Although these animals were roughly the same size , there is some evidence of niche differentiation between the two . Gorgosaurus is the best @-@ represented tyrannosaurid in the fossil record , known from dozens of specimens . These plentiful remains have allowed scientists to investigate its ontogeny , life history and other aspects of its biology . 
