Genus: Lythronax LOEWEN, IRMIS, SERTIH, CURRIE & SAMPSON, 2013
Etymology: Greek, lythron, "gore" and Greek, anax, "king."

Species: argestes LOEWEN, IRMIS, SERTIH, CURRIE & SAMPSON, 2013
Etymology: Greek, argestes, the Homeric wind from the southwest, in reference to the geographic location of the specimen within North America.

Holotype: UMNH VP 20200

Locality: UMNH VP Locality 1501, near Nipple Butte, Grand Staircase-Escalante National Monument (GSENM), Kane County, Utah.

Horizon: Lower part of the middle member of the Wahweap Formation.

Biostratigraphy:

Age: Middle Campanian Stage, Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Right maxilla, both nasals, right frontal, left jugal, left quadrate, right laterosphenoid, right palatine, left dentary, left splenial, left surangular, left prearticular, a dorsal rib, a caudal chevron, both pubes, left tibia, left fibula, and left metatarsals II and IV.

Lythronax argestes (modified from LOEWEN, et. Al., 2013) UMNH VP 20200.