Shunosaurus
| Key | Value |
|---|---|
| Name Meaning | “Shu lizard” |
| Location | China (Sichuan) |
| Time Period | c. 161 million years ago (Middle – Late Jurassic) |
| Length | 31 ft (9.5 m) |
| Weight | 3.5 tons (3,250 kg) |
| Locomotion | Quadruped |
| Diet | Herbivore |
| Described | 1983 (Dong et al.) |
| Geological Formation(s) | Shaximiao |
| Valid Species | Shunosaurus lii (type), Shunosaurus jiangyiensis |
Phylogeny: Dinosauria > Saurischia > Sauropodomorpha > Plateosauria > Massopoda > Sauropodiformes > Sauropoda > Gravisauria > Eusauropoda
Overview: Scientifically described as a genus in 1983, Shunosaurus derives part of its name from an ancient state known as “Shu” that was located in what is now Sichuan Province, in southern China. The state was later absorbed into the sphere of imperial China, though its name is still used today to refer to Sichuan, so Shunosaurus can also mean “Sichuan lizard”. Shunosaurus fossils were first found in Sichuan by a team of student paleontologists, in the 1970’s. Multiple specimens have been found, making Shunosaurus one of the better understood sauropods of its time. Older sources cite Shunosaurus as having lived in the Late Jurassic, but later studies would find it lived earlier, towards the latter part of the Middle Jurassic. All known fossils of Shunosaurus come from China’s famous Shaximiao Formation, specifically from its lower layers. It possibly coexisted with other dinosaurs like Omeisaurus, Agilisaurus, Huayangosaurus, and the carnivorous Gasosaurus.
Phylogenetically, there has been some disagreement over how Shunosaurus should be classified. It does seem to have been a fairly basal sauropod, however, typically placed within the Eusauropoda as a basal member. Originally, it was classified as a member of the family Cetiosauridae, though in later studies, this has found little support. It’s sometimes associated with Mamenchisaurus and its kin, in the Mamenchisauridae, but it probably wasn’t a member itself. Shunosaurus wasn’t all that large, being around nine or ten meters long. Its skull was boxy and deep, with a sloping snout. The teeth were fairly “primitive”, with a spoon-like shape. Shunosaurus probably fed mainly upon mid-level vegetation. Its most famous feature, which wasn’t recognized when it was first described, was a small club on the end of its tail, capped by spines, probably used for physical defense. Clubs have been found on some other Chinese sauropods, including mamenchisaurids.