In 2014, Quetecsaurus was initially described and named by Bernardo González Riga and Leonardo Ortiz David, with its type designation being Quetecsaurus rusconii. The known remains of this dinosaur are solely represented by the holotype, which includes a partial skeleton found in close association. The holotype encompasses a postorbital, teeth, the atlas, a rear cervical vertebra, an incomplete dorsal vertebra, a rear caudal centrum, dorsal ribs, a coracoid, five metacarpals, and fragments of a humerus, radius, and ulna. These fossilized remains were collected from red mudstone within the Cerro Lisandro Formation, located in the Neuquén Basin. The dating indicates it originates from the middle or late Turonian stage of the Late Cretaceous period. The specimen represents the first sauropod with well-preserved materials found within this particular formation.