In 1938, three dinosaur bone beds were excavated, and ceratopsian material was collected from Big Bend National Park (Texas) by William Strain.
This material was studied by Lehman in 1989 and named Chasmosaurus mariscalensis.
It is known only from the holotype UTEP P.37.7.086 a partial adult skull which includes a braincase, left supraorbital horncore, left maxilla and a right dentary.
Additional material was associated with the holotype, but not considered to be part of it.
All specimens of Agujaceratops were collected from the lower part of the Upper Shale member of the Aguja Formation, dating to about 77 million years ago, in the Big Bend National Park, Brewster County.
Additional material was recovered from elsewhere in west Texas, including a nearly complete skull from Rattlesnake Creek.

Originally described as Chasmosaurus mariscalensis by Lehman in 1989, subsequent analysis resulted in the taxon being put in its own genus.
Agujaceratops was named by Spencer G. Lucas, Robert M. Sullivan and Adrian Hunt in 2006, and the type species is Agujaceratops mariscalensis.

Later, Lehman and colleagues revisited the Agujaceratops material and found substantial variation.
They described the Rattlesnake Creek skull as a new species, Agujaceratops mavericus.
In 1938, three dinosaur bone beds were excavated, and ceratopsian material was collected from Big Bend National Park (Texas) by William Strain. This material was studied by Lehman in 1989 and named Chasmosaurus mariscalensis. It is known only from the holotype UTEP P.37.7.086 a partial adult skull which includes a braincase, left supraorbital horncore, left maxilla and a right dentary. Additional material was associated with the holotype, but not considered to be part of it. All specimens of Agujaceratops were collected from the lower part of the Upper Shale member of the Aguja Formation, dating to about 77 million years ago, in the Big Bend National Park, Brewster County. Additional material was recovered from elsewhere in west Texas, including a nearly complete skull from Rattlesnake Creek. 
Originally described as Chasmosaurus mariscalensis by Lehman in 1989, subsequent analysis resulted in the taxon being put in its own genus. Agujaceratops was named by Spencer G. Lucas, Robert M. Sullivan and Adrian Hunt in 2006, and the type species is Agujaceratops mariscalensis.
Later, Lehman and colleagues revisited the Agujaceratops material and found substantial variation. They described the Rattlesnake Creek skull as a new species, Agujaceratops mavericus.
Agujaceratops