Genus: Aucasaurus CORIA, CHAIPPE & DINGUS, 2002
Etymology: Mapuche language, « Auca », in reference to Auca Mahuevo, the fossil locality where the specimen was found, and Greek, sauros, "lizard."

Species: garridoi CORIA, CHIAPPE & DINGUS, 2002
Etymology : In honor of Mr. Alberto Garrido, who discovered the holotype;
= Genus: Nova CORIA, CHIAPPE & DINGUS, 2000

Holotype: MCF-PVPH-236

Locality: Auca Mahuevo, near Mina La Escondida, in the northerastern corner of the Province of Neuquen, northwestern Patagonia, Argentina.

Horizon: Rio Colorado Formation, Anacleto Member.

Biostratigraphy:

Age: Coloradoan Tetrapoda Assemblage, Santonian-Campanian Stage, Senonian Subepoch, Gulf Epoch, Late Cretaceous.

Material: Skull and nearly complete skeleton.
Note: Traces of soft tissue around the pelvis.
Note: Caudals 5 and 6 are pathologically fused to each other.