Sinotyrannus
Sinotyrannus (meaning "Chinese tyrant") 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 much 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 , and was the largest known theropod from the Jiufotang Formation. The type species is S. kazuoensis, described by Ji et al., in 2009. Description Sinotyrannus was a large tyrannosaur, measuring long and weighing . It was among the largest basal tyrannosauroids known, repudiating the previously presumed trend that tyrannosauroids gradually increased in size throughout the Cretaceous period from small basal forms like Dilong to advanced apex predators such as Tyrannosaurus. The holotype, KZV-001, consists of a disarticulated partial skeleton including the front portion of the skull, three dorsal vertebrae, the incomplete ilia, three articulated manual phalanges (including an ungual), and other fragmentary bones. The preserved cranial elements include