Sinraptor
Sinraptor is a genus of metriacanthosaurid theropod dinosaur from the Shishugou Formation China. Sinraptor and its close relatives were among the earliest members of the Jurassic carnosaurian radiation. Sinraptor still remains the best-known member of the family Metriacanthosauridae, with some older sources even using the name "Sinraptoridae" for the family.
Discovery and naming
The holotype specimen of Sinraptor was uncovered from the Shishugou Formation during a joint Chinese/Canadian expedition to the northwestern Chinese desert in 1987 and described by Philip J. Currie and Zhao Xijin in 1994. Standing nearly tall and measuring roughly in length, two species of Sinraptor have been named. S. dongi, the type species, was described by Currie and Zhao in 1994. A second species, originally named Yangchuanosaurus hepingensis by Gao in 1992, may actually represent a second species of Sinraptor. Whether or not this is the case, Sinraptor and Yangchuanosaurus were close relatives and are classified together in the family Metriacanthosauridae.The name Sinraptor comes from the Latin prefix "Sino", meaning Chinese, and "raptor", meaning robber. The specific name dongi honours Dong Zhiming. Despite its name, Sinraptor is not related to dromaeosaurids like Velociraptor. Instead, it was a carnosaur distantly related to Allosaurus.Description
proposed that S. dongi would reach in length and in body mass, while Holtz estimated it to be in length.The dentition of Sinraptor was very similar to that of Allosaurus and indicated that it likely would have preyed upon medium-sized dinosaurs such as stegosaurs by using its blade-like teeth to inflict massive, fatal wounds.