Oviraptor

*Oviraptor philoceratops*

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***Oviraptor*** is a genus of small Mongolian theropod dinosaurs, first discovered by the paleontologist Roy Chapman Andrews, and first described by Henry Fairfield Osborn, in 1924. Its name is Latin for 'egg thief', referring to the fact that the first fossil specimen was discovered atop a pile of what were thought to be *Protoceratops* eggs, and the specific name *philoceratops* means "lover of ceratopsians", also given as a result of this find. In his 1924 paper, Osborn explained that the name was given due to the close proximity of the skull of *Oviraptor* to the nest (it was separated from the eggs by only four inches of sand). However, Osborn also suggested that the name *Oviraptor* "may entirely mislead us as to its feeding habits and belie its character". In the 1990s, the discovery of nesting oviraptorids like *Citipati* proved that Osborn was correct in his caution regarding the name. These finds showed that the eggs in question probably belonged to *Oviraptor* itself, and that the specimen was actually brooding its eggs.

*Oviraptor* lived in the late Cretaceous period, during the late Campanian stage about 75 million years ago; only one definitive specimen is known (with associated eggs), from the Djadokhta Formation of Mongolia, though a possible second specimen (also with eggs) comes from the northeast region of Inner Mongolia, China, in an area called Bayan Mandahu.

## Description

*Oviraptor philoceratops* is known from a single partial skeleton (specimen number AMNH 6517), as well as a nest of about fifteen eggs that have been referred to this species (AMNH 6508).

When living, *Oviraptor* was one of the most bird-like of the non-avian dinosaurs. Its rib cage, in particular, displayed several features that are typical of birds, including a set of processes on each rib that would have kept the rib cage rigid. A relative of *Oviraptor* called *Nominga* was found with a pygostyle, which is a set of fused vertebrae that would later help support the tail feathers of birds. Skin impressions from more primitive oviraptorosaurs, like *Caudipteryx* and *Protarchaeopteryx*, clearly show an extensive covering of feathers on the body, feathered wings and feathered tail fans. A tail fan is also indicated by the presence of a pygostyle in *Nomingia*, suggesting that this feature was widespread among oviraptorosaurs. Additionally, the nesting position of the brooding *Citipati* specimens implies the use of feathered wings to cover the eggs. Given the close anatomical similarity between these species and *Oviraptor*, it is highly likely that *Oviraptor* had feathers as well.

*Oviraptor* is traditionally depicted with a distinctive crest, similar to that of the cassowary. However, re-examination of several oviraptorids show that this well-known, tall-crested species may actually belong to the genus *Citipati*, a relative of *Oviraptor*. It is likely that *Oviraptor* did have a crest, but its exact size and shape are unknown due to crushing in the skull of the only recognized specimen.

## Classification

*Oviraptor* was originally allied with the ornithomimids by Osborn due to its toothless beak. Osborn also found similarities with *Chirostenotes*, which is still considered a close relative of *Oviraptor*. In 1976, Barsbold erected a new family to contain *Oviraptor* and its close kin, making *Oviraptor* the type genus of the Oviraptoridae.

    While the original specimen of *Oviraptor* was poorly preserved, especially the crushed and deformed skull, new and more complete oviraptorid specimens were assigned to the genus in the 1970s and 1980s. In 1976, Barsbold referred six additional specimens to the genus *Oviraptor* (including IGM 100/20 and 100/21), but these were later reclassified in the new genus *Conchoraptor*. Another specimen, IGN 100/42, is perhaps the most famous, owing to its well-preserved complete skull and large size. This specimen was referred to the genus *Oviraptor* by Barsbold in 1981 and came to represent *Oviraptor* in most popular depictions and in scientific studies of oviraptorids. However, this specimen, with its distinctive tall, cassowary-like crest, was re-examined by the scientists who described the nesting oviraptorids, and found to resemble them more closely than the original specimens of *Oviraptor*. For this reason, they removed IGN 100/42 from the genus *Oviraptor*, provisionally re-classifying it as a species of *Citipati*.

## Paleobiology

As its name suggests, *Oviraptor* was originally presumed to have eaten eggs, based on its association with a fossilized nest (specimen number AMNH FR 6508) thought to belong to *Protoceratops*. The idea of a crushing jaw was first proposed by H. F. Osborn, who believed that the toothless beak of the original skull, together with an extension of several bones below the jaw from the palate, would have made an "egg-piercing" tool. In 1977, Barsbold argued that the strength of its beak would indicate that it was strong enough to break the shells of mollusks such as clams, which are found in the same geological formation as *Oviraptor*. These bones form part of the main upper jaw bone or maxilla, which converge in the middle to form a pair of prongs. The rest of the bony palate, unlike all other dinosaurs, is extended below the jaw line and would have pushed into the space between the toothless lower jaws. A beak (*rhamphotheca*) covered the edges of upper and lower jaws and probably the palate, as proposed by Barsbold and Osborn.

The discovery of nesting specimens of the related *Citiparti*, with the same types of egg in the original *Oviraptor* specimen, showed that the eggs actually belonged to *Oviraptor*, not *Protoceratops*, and that the type specimen was likely brooding the eggs, not feeding on them. While this discovery did not rule out the possibility that *Oviraptor* included eggs in its diet, its exact feeding strategies remain unknown. The only *Oviraptor philoceratops* skeleton preserved the remains of a lizard in the region of its stomach cavity, implying that the species was at least partially carnivorous.

## JPInstitute.com Description

Oviraptor is a very unique dinosaur with some rather strange features. Instead of teeth, it has a beak and something not seen in any other dinosaur, two teeth in the roof of its mouth. The reason it got its name is that when it was first discovered, Oviraptor was sitting on a nest of eggs. It was thought it was stealing the eggs of another dinosaur. Years later, it was found that the eggs were its own and that it was trying to protect them from an approaching sandstorm.

Oviraptor has another unusual feature - it has a thin crest of bone on its forehead. This crest seems to have grown and changed throughout its entire life. It may have been used as a form of individual identification or to differentiate gender. Also, different species of the Oviraptor genus had different crests. It is not clear what Oviraptor ate. Since it was probably not eggs, and it had very strong jaws, some think it would have eaten shellfish that it could easily crack open. Others argue that it must have been an herbivore as its skull did not show characteristics for meat-eating.

Of particular note is that an as yet undescribed North American Oviraptor was discovered in 1996 in South Dakota. This specimen is very large, almost 20 feet long. A trackway has also been associated with this find.

## Dinosaur Field Guide Description

Oviraptor (egg hunter") is dinosaur once thought to have been an egg hunter. It is now known to have been an egg protector! When paleontologists first found this little meat-eater in the Mongolian desert, it was sitting on top of a bunch of fossilized eggs. The scientists thought these eggs were from the horned dinosaur Protoceratops. Knowing that Oviraptor was a theropod, or meat-eating dinosaur, the scientists guessed that Oviraptor was about to eat the eggs. Many decades later, however, paleontologists discovered that these eggs were actually Oviraptor eggs, and that (like birds) Oviraptors sat on their eggs before they hatched. Since then, many Oviraptor nests (and nests of related dinosaurs) have been found with parents on top. Oviraptor is one of the oviraptorosaur dinosaurs. Like other Late Cretaceous oviraptorosaurs, Oviraptor had a deep, toothless beak. It also had long, grasping hands, which would have been useful for clutching food. The exact diet of Oviraptor is debated by paleontologists. The first skeleton of Oviraptor contained a lizard skeleton in its belly, so it definitely ate some meat. Some paleontologists, however, think that it may have eaten plants.

### Fun Facts

Oviraptor's skull was so unusual that, when it was first being dug out of the rock, paleontologists were not sure which and was the front!

### Trivia

Oviraptor was originally going to be named Fenestrosaurus("window lizard") because of the openings in its skull, but the paleontologist who
named it thought that "egg hunter" was a more interesting.

## Links

https://web.archive.org/web/20040806054124fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_ovira.html

## References

1. ↑ 1.0 1.1 1.2 Osborn, H.F. (1924). "Three new Theropoda, *Protoceratops* zone, central Mongolia." *American Museum Novitates,* **144**: 12 pp., 8 figs.; (American Museum of Natural History) New York. (11.7.1924).
2. ↑ Dong and Currie, P. (1996). "On the discovery of an oviraptorid skeleton on a nest of eggs at Bayan Mandahu, Inner Mongolia, People's Republic of China." *Canadian Journal of Earth Sciences*, **33**: 631-636.
3. ↑ Paul, G.S. (2002). *Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds.* Baltimore: Johns Hopkins University Press.
4. ↑ 4.0 4.1 Clark, J.M., Norell, M.A., & Barsbold, R. (2001). "Two new oviraptorids (Theropoda:Oviraptorosauria), upper Cretaceous Djadokhta Formation, Ukhaa Tolgod, Mongolia." *Journal of Vertebrate Paleontology* **21(2)**:209-213., June 2001.
5. ↑ 5.0 5.1 Template:Cite journal
6. ↑ Barsbold, R. (1986). "Raubdinosaurier Oviraptoren" [in Russian]. In: O.I. Vorob’eva (ed.), *Gerpetologičeskie issledovaniâ v Mongol’skoj Narod−noj Respublike*, 210–223. Institut èvolûcionnoj morfologii i èkologii životnyh im. A.N. Severcova, Akademiâ nauk SSSR, Moscow.
7. ↑ Barsbold, R. (1981). "Toothless dinosaurs of Mongolia." *Joint Soviet-Mongolian Paleontological Expedition Transactions*, **15**: 28-39. [in Russian]
8. ↑ Barsbold, R., Maryanska, T., and Osmolska, H. (1990). "Oviraptorosauria," in Weishampel, D.B., Dodson, P., and Osmolska, H. (eds.). *The Dinosauria*. Berkeley: University of California Press, pp. 249-258.
9. ↑ (1995) "Discovering Dinosaurs" U. of California Press
10. ↑ Norell, Clark, Chiappe, and Dashzeveg, (1995). "A nesting dinosaur." *Nature*, **378**: 774-776.