 While earlier tyrannosauroids are found on all three northern continents , tyrannosaurid fossils are known only from North America and Asia . Sometimes fragmentary remains uncovered in the Southern Hemisphere have been reported as " Southern Hemisphere tyrannosaurids , " although these seem to have been misidentified abelisaurid fossils . The exact time and place of origin of the family remain unknown due to the poor fossil record in the middle part of the Cretaceous on both continents , although the earliest confirmed tyrannosaurids lived in the early Campanian stage in western North America . 
