Genus: Xiaosaurus DONG & TANG, 1983
Etymology: Chinese, xiao, “dawn”, and Greek, sauros, "lizard": Dawn lizard.
= Xiaosaurus DONG, 1983 (nomen nudum)

Species: dashanpensis DONG & TANG, 1983
Etymology: In reference to Dashanpu, where the specimen was found.
= Xiaosaurus dashanpensis DONG, 1983 (nomen nudum)

Holotype: IVPP V6730A (field no. Cr. 003)

Locality: Dashanpu (Dashanpu Dinosaur Quarry), lat. 29°5’N, long. 104°50’E, situated 11 km east of Zigong City, 250 km south of Chengdu, Hechuan County, Sichuan Basin, Sichuan (Szechwan) Province, China.

Horizon: Xaishaximiao (Shaximiao) Formation.

Biostratigraphy:

Age: Bathonian-Callovian Stage, Dogger Epoch, Middle Jurassic.

Note: Bajocian (CHEN et al. 1982), Lower Middle Dogger Epoch, Middle Jurassic.

Material: Fragment of maxilla with tooth (A), 2 conjoined cervical vertebrae (B), axis, sacral vertebrae, 3 caudal vertebrae, left humerus (C), femur (D), fibula, tibia (E), metatarsals 3 and 4, phalanges of 3 and 4 (F, G).

Referred material:

IVPP V6730B: 1 complete right femur, one dorsal vertebra, 2 articulated sacral vertebrae, a phalanx, a rib, and 2 isolated teeth.

SDM 6015: Humerus.