Genus: Sonorasaurus RATKEVICH, 1998
Etymology: From the Hispanicized Opata Indian term, Sonora, referring to the Sonora River, used here as being part of the greater Sonoran Desert region as a general province, and Greek, sauros, “lizard”: Sonoran Lizard.

Species: thompsoni RATKEVICH, 1998
Etymology: In honor of Richard Thompson, who discovered the specimen.

Holotpe: ASDM 500

Locality: “Sonorasaurus” Quarry, southwestern foothills of Whetstone Mountains, Pima County, Arizona.

Horizon: Turney Ranch Formation, Bisbee Group.

Biostratigraphy:

Age: Albian Stage, Middle Gallic Subepoch, Upper Early Cretaceous Epoch, Early Cretaceous.

Material: Left ulna, radii, left (?) complete McI, complete McII, proximal and distal ends of McIII (?), proximal and distal ends of McIV (?), distal ½ and marginal elements of left ilium, distal 1/3 of ischium, acetabulum, medial portions of pubis and possible ischium, distal half of left femur, midschaft of right ulna, left tibia (?), left fibula, partial right fibula (?), MtI, MtII, MtIV, MtV, phalanx I-1, phalanx II-1, phalanx IV-1, phalanx II-3, ungual digit 1, ungual digit 2, first (?) second (?), and third dorsal vertebrae, caudal vertebrae 5-12 (est), cheveron fragments, dorsal and cervical ribs, and 2 gastroliths.