Yangchuanosaurus Click to enlarge image
Image: James Reece
© Australian Museum

Fast Facts

  • Classification
    Species
    shangyouensis
    Genus
    Yangchuanosaurus
    Family
    Metriacanthosauridae
    Super Family
    Allosauroidea
    Order
    Avetheropoda
    Phylum
    Chordata
    Kingdom
    Animalia
  • Number of Species
    Two- Y. shangyouensis and Y. zigongensis
  • Size Range
    Up to 8 metres long; weight estimated at 1.44 tons.
  • Feeding Habits
    carnivorous

Introduction

Yangchuanosaurus shangyouensis

Pronounced YAHNG-CHWAHN-oh-SAWR-us

Meaning Lizard from Yang-ch’uan. The species name, shangyouensis, refers to the Shangyou Reservoir Dam, where labourers digging foundations for the Shangyou Reservoir Dam uncovered the first skeleton.
Yangchuanosaurus was a large carnivore which lived around 168-157 million years ago. It was likely a top predator in China at that time and preyed on other dinosaurs such as Mamenchisaurus.

This large carnivorous dinosaur was an allosaur, not a tyrannosaur.

Identification

Yangchuanosaurus shangyouensis had:

  • dagger-like, curved teeth to help grasp prey;
  • six large holes in the skull to help reduce its weight for better mobility;
  • forward-facing eyes which gave it good depth perception;
  • a long tail to help balance its body when running.

Compared to T. rex, Yangchuanosaurus was smaller and lighter, with longer arms. Like T. rex, it had a large skull, powerful legs.


Habitat

This dinosaur was found in Shangyou Reservoir, within the Shangshaximiao Formation, a Late Jurassic mudstone in China.

Distribution

This dinosaur has only been found in Yangchuan county, Sichuan, China.

Feeding and diet

When Yangchuanosaurus roamed, tyrannosaurs were small and relatively primitive. They would have competed with and possibly tried to evade Yangchuanosaurus.

Fossils description

Yangchuanosaurus shangyouensis was named after the Shangyou reservoir in Yangchuan county, Sichuan. It was found during the construction of this reservoir in 1979.
In 1981, fossils of this species were nearly lost in a flood as the Chongqing Museum of Natural History laboratory was partially submerged. Thankfully the museum technicians and fossil material were not harmed in the incident.

Evolutionary relationships

Yangchuanosaurus shangyouensis was a large theropod. It belonged to the superfamily Allosauridae that occurred worldwide in the Late Jurassic to Early Cretaceous.