Genus: Piatnitzkysaurus BONAPARTE, 1979
Etymology: In honor of Alejanddro Piatnitzky, Russian -born Argentine geologist, who studied Mesozoic stratigraphy in the 1930s and 1940s, and Greek, sauros, "lizard."
= Piatnitzkisaurus KURZANOV, 1989 (sic)
= Pitnitzkyosuarus LINDSAY, 1991 (sic)

Species: floresi BONAPARTE, 1979
Etymology: In honor of geologist Miguel Alejandro Flore.

Holotype: PVL 4073

Locality: 1 km east of store de Farias, Cerro Condor, Chubut Province, Patagonia, Argentina.

Horizon: Canadon Asfalto Formation.

Biostratigraphy:

Age: Callovian Stage, Upper Dogger Epoch, Middle Jurassic.

Material: Occipital region, cranium, frontal and maxillae, anterior part of both dentaries, 13 vertebrae, axis, cervicals, dorsals, some incomplete, 4 incomplete sacrals, anterior caudals, ribs, scapulae, coracoids, right humerus, left ulna, fragments of ilia, pubis and ischium, femora, tibia and fibula.

Hypodigm:

MACN CH 895: Fragmentary left maxilla, left humerus, proximal end of both pubes, ischia, right tibia, metatarsals II, III, IV, incomplete sacrum (4 vertebrae), posterior dorsal vertebrae and ribs.