Tyrannasaurus Spitter.gif|Tyrannosaurus Tarbosaurus5.jpg|Tarbosaurus Gorgosaurus.png|Gorgosaurus Tyrannosauroids are a clade/superfamily of basal tyrannoraptoran theropod dinosaurs, and include the infamous tyrannosaurids. Primitive Tyrannosauroids are found on all northern hemisphere continents and they have first evolved in the middle Jurassic period and died out by the middle of Cretaceous, as more advanced tyrannosaurs took over their niche(although one genus, Dryptosaurus, had reached the end of the cretaceous despite being a Tyrannosauroid).