Yangchuanosaurus was the apex predator of Mid Jurassic China. Reaching a length of 11.5 meters, it was the largest of the Metriacanthosauridae family.
Yangchuanosaurus is an extinct genus of Metriacanthosaurid Theropod dinosaur that lived in China from the Middle Jurassic to Early Cretaceous periods (Bathonian to Berriasian stages), and was similar in size and appearance to its North American and European relative, Allosaurus. Yangchuanosaurus hails from the Upper Shaximiao Formation and Suining Formation and was the largest predator in a landscape that included the sauropods Mamenchisaurus and Omeisaurus and the stegosaurs Chialingosaurus, Tuojiangosaurus and Chungkingosaurus. This theropod was named after the area in which was discovered, Yongchuan, in China. Yangchuanosaurus lived alongside another Metriacanthosaurid, Sinraptor. Sinraptor was a formidable hunter, and like Yangchuanosaurus, it too was found in the Shaximiao Formation. Sinraptor has been known from two species, which have been uncovered in the Shishugou Formation. It has been proven that Sinraptor had a length of about 7.6-8.8 meters. Which made Sinraptor one of the largest predators from Mid Jurassic China. The type specimen of Y. shangyouensis had a skull 82 centimeters (2.69 ft) long, and its total body length was estimated at 10.8 meters. Another specimen, assigned to the new species Y. magnus, was even larger, with a skull length of 1.11 meters (3.6 ft). It may have been up to 11.5 meters long, and weighed as much as 3.4 metric tons (3.7 short tons). Gregory S. Paul suggested that these are the same species and gave a length of 11 meters (36 feet) and a weight of 3 metric tons (3.3 short tons). There was a bony ridge on its nose and multiple hornlets and ridges, similar to Ceratosaurus. Yangchuanosaurus was a large, powerful meat-eater. It walked on two large, muscular legs, had short arms, a strong, short neck, a big head with powerful jaws, and large, serrated teeth. It had a long, massive tail that was about half of its length. The first digit of its foot was a small dewclaw. The three outer toes were used to bear weight and each was equipped with a large claw.