The Agujaceratops was herbivorous dinosaur that existed on the earth in the late Cretaceous Period of the Mesozoic Era. It was a ceratopsian reptile, which belonged to the same group of dinosaurs that included the famous Triceratops. The fossils of both the above mentioned dinosaurs were found in North America. The Agujaceratops, however, preceded the Triceratops by about 7 to 8 million years.
The period of existence of this animal is estimated to be around 80 to 76 million years ago. This lies in the Campanian age. It is also possible that this dinosaur was also present during the early years of the Maastrichtian age. Just like all other ceratopsids, the Agujaceratops had an expanded skull, which showed frills and horns. The purpose of this adaptation is still debated by paleontologists.
The size of the Agujaceratops is yet not properly deduced due to scarcity of fossil evidence. But based on comparisons with other ceratopsids, it is assessed that its length was 4.5 to 5 meters and its weight was 750 to 1500 kilograms.
- The word ‘Aguja’ is derived from the Aguja Formation in Texas, where the remains of the Agujaceratops were discovered. The suffix ‘ceratops’ is formulated from two Greek words. The Greek term for ‘horn’ is ‘korna’ and that for face is ‘prosopo’. Thus, ‘ceratops’ roughly translates to ‘horn faced’; and it follows that Agujaceratops is supposed to denote ‘the horn faced creature from Aguja’.
- The binomial name A. mariscalensis is framed from the Mariscal Mountain Range in Texas, near which the bones of the Agujaceratops were unearthed. The suffix ‘ensis’ has Latin roots and is used to denote ‘hailing from’.
- The generic name of the dinosaur was coined by scientists Spencer Lucas, Robert Sullivan and Adrian Hunt while the specific name was chosen by Thomas Lehman.
Discovery of fossils
The remains of the Agujaceratops were found in the Aguja Formation. This structure lies in the Big Bend Nation Park in the Brewster County in Texas. The holotype was discovered in the year 1938 by William Strain. He was a member of the Works Progress Administration team and they had discovered over 300 bones in the Big Bend. As most of these bones were unlike any dinosaur paleontologists had seen, they remained unclassified.
The classification of the Agujaceratops was not an easy task as most of the known ceratopsids were defined in the 1990s.
- The bones of the Agujaceratops caught the attention of scientist Thomas Lehman in the late 1980s, about five decades after they were discovered. He compared them to the remains of the Chasmosaurus, a Canadian dinosaur that and was defined in 1987, just one year prior to him examining the remains. Lehman found that although the Canadian specimen had shorter horns, it still resembled the Texan dinosaur better than any other known specimen.
- In 1993, paleontologist Catherine Forster examined the cranium of the Agujaceratops and concurred with Lehman. She concluded that the southern species was a long horned variant of the northern species. This belief was held firm till the mid-2000s.
- But in the year 2006, scientist Spencer Lucas published a paper stating that the Texan remains which were attributed to the Chasmosarus belonged to a separate genus. He found that southern ceratopsids like the Utahceratops and the Kosmoceratops had much longer horns and wider frills than their northern counterparts. He named the Texan dinosaur as ‘Agujaceratops’.
- Presently, the Agujaceratops is classified in order Ornithischia, family Ceratopsidae and sub family Chasmsaurinae.
Nature of fossils
Only a few bones are attributed to the Agujaceratops currently. These include partial bones of the cranium including the temporals, parietals and occipital. Fragments of the nasal bones, the left maxilla and the right half of the mandible were also included in the holotype. Since then, limb bones such as the humerus, radius, femur, tibia and fibula were also found.
The Aguja Formation
The Aguja Formation is a part of the Tronillo Group of North America. It lies partly in Texas in the United States and partly in Chihuahua, Mexico. The Pen Formation lies below it and the Javelina Formation overlies it. The fossils in its lowest part date back 80 million years ago while those on its upper portion are about 70 to 68 million years old.
The fossils of many vertebrate and invertebrate species have been discovered here. These included dinosaurs such as the Agujaceratops, Edmontonia, Kritosaurus, etc. The large crurotarsan Deinosuchus was also uncovered here.
- The Agujaceratops was a moderately large ceratopsid. Its length is expected to be around 15 feet. Its weight is calculated based on the length of its femur, and is found to be about .8 to 1.3 tons.
The lack of fossil evidence necessitates these conjectures.
- The head of this species was expanded. It had a moderately sized nasal horn, while its frills were long and triangular. The skull also showed prominent brow horns.
- The jaw of the Agujaceratops was elongated and pointed like a beak.
- Its forelimbs and hind limbs were almost of a similar size, indicating that it was quadrupedal.
- The tail of this dinosaur was medium sized and strong.
- Its overall build was stout and stocky.
Habits and habitats
The Agujaceratops was plant eating reptile. The special shape of its snout facilitated a browsing habit. It was obviously terrestrial and derived its nourishment from shrubs and grasses.
The purpose of the enlarged skull processes can be multifold. Many scientists believe that they could be for display during courtship rituals. The other function could be for offense or defense. Tyrannosaurus fossils had marks of Triceratops nasal bosses on their fossils, which indicates that they were used for attacking purposes but this cannot necessarily be extrapolated to the Agujaceratops. And Agujaceratops belonged to a different sub family as compared to the Triceratops.
The remains of the dinosaur are believed to have been found in an area that could have been a Cretaceous swamp. This could indicate that its habitat was a swamp or that it was pulled there to be devoured by the Deinosuchus, which coexisted with it.
The Agujaceratops is related to the Chasmosaurus and Pentaceratops, but not an ancestor of the Pentaceratops as previously believed.
The fossils of the Agujaceratops were among the first ceratopsid remains to be defined. They have tremendously helped paleontologists under ornithischian dinosaurs.