Huayangosaurus is a
genus of
stegosaurian dinosaur from the Middle
Jurassic of
China. The name derives from "Huayang" (華陽), an alternate name for
Sichuan (the province where it was discovered), and "saurus", meaning "lizard". It lived during the
Bathonian to
Callovian stages, around 165 million years ago, some 20 million years before its famous relative,
Stegosaurus appeared in North America. At only 4.5 metres long, it was also much smaller than its famous cousin. Found in the Lower Shaximiao Formation,
Huayangosaurus shared the local Middle Jurassic landscape with the
sauropods Shunosaurus,
Datousaurus,
Omeisaurus and
Protognathosaurus, the
ornithopod Xiaosaurus and the carnivorous
Gasosaurus. It was found in
Huayang in
China.