Tyrannosauridae is a family of coelurosaurian theropod dinosaurs that comprises two subfamilies containing up to thirteen genera, including the eponymous Tyrannosaurus. The exact number of genera is controversial, with some experts recognizing as few as three. All of these animals lived near the end of the Cretaceous Period and their fossils have been found only in North America and Asia.
Deinodon teeth, the earliest known tyrannosaurid remains
Teeth that have been assigned to Aublysodon at various times
Labelled Daspletosaurus skull
Tyrannosauroidea is a superfamily 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.
Size of some small genera, compared to a human.
Skull and neck of Daspletosaurus, from the Field Museum of Natural History in Chicago.
Skull of Proceratosaurus, a proceratosaurid tyrannosauroid from the Middle Jurassic of England.