Agujaceratops
A horned dinosaur from the Late Cretaceous of Texas.
Agujaceratops, whose name translates to "horned face from Aguja," is a genus of chasmosaurine ceratopsid dinosaur that lived during the Late Cretaceous (Campanian) in what is now western Texas. It is known from two species, *A. mariscalensis* and *A. mavericus*, both recovered from the Aguja Formation.
The first fossils were collected in 1938 from three dinosaur bone beds in Big Bend National Park by William Strain. In 1989, Lehman studied this material and named it *Chasmosaurus mariscalensis*, based on a partial adult skull (the holotype) that includes a braincase, left supraorbital horncore, left maxilla, and right dentary. Additional bones found nearby were not considered part of the holotype. All specimens come from the lower part of the Upper Shale member of the Aguja Formation, dating to about 77 million years ago. Later, more material was found elsewhere in west Texas, including a nearly complete skull from Rattlesnake Mountain. In 2006, Spencer G. Lucas, Robert M. Sullivan, and Adrian Hunt placed the taxon in its own genus, naming it *Agujaceratops mariscalensis*. Subsequently, Lehman and colleagues revisited the material, noted substantial variation, and described the Rattlesnake Mountain skull as a second species, *Agujaceratops mavericus*.
This dinosaur was relatively large, reaching about 4.3 meters (14 feet) in length and weighing around 1.5 metric tons (1.7 short tons). It resembled other chasmosaurines like *Pentaceratops*, with a short nose horn, long brow horns, and an elongated frill bordered by small hornlets. The back of the frill has a strong notch, giving it a heart shape, and bears three or four pairs of spike-like hornlets. The frill edges have numerous low, blunt hornlets, creating a strongly scalloped look. The brow horns point up and out, curving backward in side view. The two species differ: *A. mavericus* has shorter brow horns and a shorter frill compared to *A. mariscalensis*.
Like other ceratopsids, *Agujaceratops* was a four-legged plant eater. Its elaborate frill and horns likely played a role in social behavior, such as displays or fights over territory or mates. Multiple individuals have been found in a single quarry, though it is unclear whether this represents animals gathered by drought or flood, or a herd. While large bonebeds of centrosaurine ceratopsids are common, they are rarer for chasmosaurines. At the time,
- length
- 4.3 meters (14 ft)
- mass
- 1.5 metric tons (1.7 short tons)
- time_period
- Late Cretaceous (Campanian), about 77 million years ago
- location
- Western Texas, USA (Aguja Formation, Big Bend National Park)
- diet
- Herbivore
- known_for
- Short nose horn, long brow horns, elongate frill with scalloped edges and a heart-shaped notch
Lore & Background
In 1938, three dinosaur bone beds were excavated in Big Bend National Park by William Strain, yielding ceratopsian material. This material was studied by Lehman in 1989 and named Chasmosaurus mariscalensis, known only from a partial adult skull. Later analysis led to the creation of a new genus, Agujaceratops, named by Spencer G. Lucas, Robert M. Sullivan, and Adrian Hunt in 2006, with the type species A. mariscalensis. Additional material from Rattlesnake Mountain was later described as a second species, A. mavericus, by Lehman and colleagues.
Reader's Guide
Agujaceratops is significant as a chasmosaurine ceratopsid that helps clarify the diversity and evolution of horned dinosaurs in the southern United States during the Late Cretaceous. Its fossils, found in the Aguja Formation, provide evidence of a swamp habitat along the western margin of the Western Interior Seaway. The presence of multiple individuals in a single quarry suggests possible social behavior, though whether from a herd or a catastrophic event is uncertain. The two recognized species, A. mariscalensis and A. mavericus, show variation in brow horn and frill length, indicating intrageneric diversity. Its elaborate frill and horns imply complex social interactions, such as displays or combat. The genus also lived alongside other dinosaurs like Leptorhynchos gaddisi and Texacephale, and faced predators including tyrannosaurs and the giant crocodilian Deinosuchus riograndensis.
Did You Know?
- Agujaceratops was originally described as Chasmosaurus mariscalensis in 1989 before being placed in its own genus in 2006.
- The name Agujaceratops means 'horned face from Aguja,' referencing the Aguja Formation.
- Two species are known: A. mariscalensis and A. mavericus, with A. mariscalensis having shorter brow horns and a shorter frill.
- Fossils of Agujaceratops were found in sediments that suggest a swamp habitat.
More in Dinosaur genera 1-24
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