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).
Tyrannosauroids were bipedal carnivores, as were most theropods, and were characterized by numerous skeletal features, especially of the skull and pelvis. Early in their existence, tyrannosauroids were small predators with long, three-fingered forelimbs.
Late Cretaceous genera became much larger, including some of the largest land-based predators ever to exist, but most of these later genera had proportionately small forelimbs with only two digits. Primitive feathers have been identified in fossils of two species, and may have been present in other tyrannosauroids as well. Prominent bony crests in a variety of shapes and sizes on the skulls of many tyrannosauroids may have served display functions.
Some primitive Tyrannosauroids also have feathers, as in the case of Dilong.
Recently, the coelurosaur Santanaraptor of South America has turned out to be a tyrannosauroid, and is one of the few tyrannosaurs found on a southern continent.