Genus: Cnephasaurus GAO & FOX, 1996
Etymology: Greek, knephas, “twilight” and Greek, sauros, “lizard”: Twilight lizard. This lizard may have been active at twilight hunting for grasshoppers, by analogy with its presumed relative, extant Crotaphytus.

Species: locustivorus GAO & FOX, 1997
Etymology: Latin, locusta, "grasshopper" and Latin, voro, "eating": grasshopper-eating”: the diet of this lizard may have consisted largely of grasshoppers, judging by its dentition.

Holotype: UALVP 29921

Locality: UALVP MR-6, Verdigris Coulee, approximately 30 km east of the Village of Milk River, Warner County, Southern Alberta Province, Canada.

Horizon: Deadhorse Coulee Member, Milk River Formation.

Biostratigraphy:

Age: Aquilian age, Late Santonian Stage, Senonian subepoch, Upper Gulf epoch, Late Cretaceous.

Material: Right maxilla having 11 well-preserved teeth and broken bases of 3 other teeth.

Tototypic UALVP 33386: Left maxillary with 4 teeth and broken bases of two others.