Tyrannosauroidea

Tyrannosauroids Temporal range: Middle Jurassic–Late Cretaceous, 166–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Six tyrannosauroids (top left to bottom right): Tyrannosaurus, Dilong, Alioramus (background) with Guanlong (foreground), Gorgosaurus, and a pair of Yutyrannus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Coelurosauria
Clade:	Tyrannoraptora
Superfamily:	†Tyrannosauroidea Osborn, 1906 (vide Walker, 1964)
Type species
†Tyrannosaurus rex Osborn, 1905
Subgroups
†Proceratosauridae †Pantyrannosauria Delcourt & Grillo, 2018 †Alectrosaurus †Dilong †Eotyrannus †Jinbeisaurus †Juratyrant †Moros †Santanaraptor †Stokesosaurus †Suskityrannus †Timurlengia †Xiongguanlong †Yutyrannus? †Megaraptora? †Eutyrannosauria Delcourt & Grillo, 2018 †Appalachiosaurus †Bagaraatan (possible chimera) †Bistahieversor †Dryptosaurus †Raptorex †Teratophoneus? †Alioramini? †Tyrannosauridae Possible tyrannosauroids †Aniksosaurus †Aviatyrannis †Chingkankousaurus †Coelurus †Labocania †Shaochilong †Siamotyrannus †Siats †Tanycolagreus †Timimus

Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinent beginning in the Jurassic Period. By the end of the Cretaceous Period, tyrannosauroids were the dominant large predators in the Northern Hemisphere, culminating in the gigantic Tyrannosaurus. Fossils of tyrannosauroids have been recovered on what are now the continents of North America, Europe and Asia, with fragmentary remains possibly attributable to tyrannosaurs also known from South America and Australia.

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.