The Agujaceratops was a herbivore from the Cretaceous period. It lived from 70 to 83 million years ago. The name means horn face from Aguja.

In 1938 the dinosaur was first discovered at the big Bend National Park by William Strain. It was not until 1989 a man named Lehman studied the fossils and described it under the Casmosaurus species. At that time there was no skull. In 1991 Paul Sereno, led an expedition at the Aguja Formation, Texas and discovered an almost complete fossil skeleton of the Agujaceatops(still named Casmosaurus). After a short study in 2006, Lucas, Sullivan and Hunt re-described it and realized that it should be its own genus and named it Agujaceratops.

The Agujaceratops is lately not considered to be an ancestor of the Pentaceratops or Chasmosaurus even though they do share a fair bit of obvious body features. The Agujaceratops has a very short frill unlike the others.