Genus: Leyesaurus APALDENTTI, MARTINEZ, ALCOBER & POL, 2011
Etymology: In honor of the Leyes family, inhabitants of the small town Balde de Leyes, who made thier discovery and notified the paleontologists of the San Juan Museum, and Greek, sauros, 'lizard'.

Species: marayensis APALDENTTI, MARTINEZ, ALCOBER & POL, 2011
Etymology: In reference to the Marayes-El Carrizal Basin, where the specimen was found.

Holotype: PVSJ 706

Locality: Balde de Leyes, Caucete Department, San Juan Province, Northwestern Argentina.

Horizon: Uppermost level, Quebrada del Barro Formation.

Biostratigraphy:

Age: Lower Jurassic?

Material: Nearly complete skull with articulated mandible, lacking both nasals, left prefrontal, middle section of the left maxilla, anterior half of the left lower jaw, supraoccipital, both exoccipitals, ophistotics, laterosphenoids and vomers, atlas-axis articulated with anterior cervical vertebrae (c3-C7), and anterior and a middle caudal vertebra, proximal region of the left scapula, coracoid and humerus, partial blade of the right pubis lacking distal and proximal ends, proximal region of both ischia, partial left pes that includs distal tarsals III and IV, metatarsal III lacking its distal end, complete metatarsals IV and V, first phalanx of digit I, second phalanx of digit II and second phalanx of digit IV.