[1] The only species is Dongyangosaurus sinensis, from which only a single fragmentary skeleton is known, coming from the Zhejiang province of eastern China.

The dorsal vertebrae were characterized by eye shaped pleurocoels and low bifurcated neural spines.

The sacrum consisted of six fused sacral vertebrae, a feature unique to somphospondylans.

Skeletal remains are rarely found; the only described dinosaurs are the sauropod Jiangshanosaurus from the Jinhua Formation, the theropod Chilantaisaurus zhejiangensis (now known to have been an indeterminate therizinosaurid theropod unrelated to Chilantaisaurus), and the nodosaurid Zhejiangosaurus from the Chaochuan Formation.

[6] The specimen was found in 2007 in the village of Baidian within the city of Dongyang, from which the generic name is derived.