Yangchuanosaurus

Yangchuanosaurus was a massive theropod dinosaur that dominated the ecosystems of Late Jurassic China. Reaching lengths between eight and over ten metres, it held an apex predator role closely comparable to that of Allosaurus in North America. Its large skull was equipped with serrated, blade-like teeth suited for slicing flesh, complemented by prominent rugose ridges running along the snout that may have supported keratinous display structures in life. Long, powerful hind limbs supported its considerable weight, while its tail provided balance during rapid movement. Known from several exquisitely preserved skeletons discovered in Sichuan, Yangchuanosaurus lived alongside diverse long-necked sauropods such as Mamenchisaurus and stegosaurs like Tuojiangosaurus, which likely formed a major part of its diet.

It possessed a series of low bony ridges and knobs along the top of its snout.

Where and when

Yangchuanosaurus lived in the Middle Jurassic, from 163.5 to 157.3 million years ago (Oxfordian age). Its remains come from China, in the Upper Shaximiao Formation.

The numbers

Length 9.3 m (estimates run from 8 to 11 m). Mass about 2.3 t. Hip height about 2.5 m. That is 5.5 human-lengths, or 0.83 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Yangchuanosaurus with a bus Place on the timeline