Genus: Rayososaurus BONAPARTE, 1996
Etymology: In reference to the Rayoso Formation and Greek, sauros, “lizard”: Rayoso Formation Lizard.
= Limaysaurus NOVAS, 1997 (nomen nudum)

Species: agrioensis BONAPARTE, 1996
Etymology: In reference to the Agrio river, Neuquen Province, Patagonia, Argentina, near where the type locality is.

Holotype: MACN-N 41

Locality: 3 km south of Agiro del Medio, Departmento Picunches, Neuquen Province, Patagonia, Argentina.

Horizon: Rayoso Formation.


Age: Lohancuran Tetrapod Assemblage, Aptian-Albian Stage, Middle Gallic Subepoch, Upper Early Cretaceous Epoch, Early Cretaceous.

Material: Complete left scapula, distal half of the right scapular blade, proximal end of a fibula, incomplete femur and fragmentary pieces of a skeleton.