Sinotyrannus is a genus of large basal tyrannosauroid dinosaur, known from a single incomplete fossil specimen including a partial skull, from the Early Cretaceous Jiufotang Formation of Liaoning, China. Specifically, it is a member of the Proceratosauridae, a family that originated in the Jurassic whose members are known from Europe and Asia. Though it is not significantly younger than primitive tyrannosauroids such as Dilong, it is similar in size to later forms such as Tyrannosaurus. It was much larger than contemporary tyrannosauroids, reaching a total estimated length of 9–10 m (30–33 ft), and was the largest known theropod from the Jiufotang Formation. The type species, S. kazuoensis, was described by Ji et al. in 2009.
Life reconstruction of S. kazuoensis
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.
Tyrannosauroidea
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.