Period: Late Cretaceous
Order, Suborder, Family: Saurischia, Theropoda, Caenagnathidae
Location: Asia (Mongolia)
Length: 6 feet (1.8 meters)
The first specimen of Oviraptor was discovered by the American Museum of Natural History expedition to Asia in 1923. It was found in the Gobi Desert of Mongolia. This is the same place that Protoceratops was found. The specimen was an almost complete skull along with parts of the hands and neck vertebrae (bones in the spine). It was found lying next to a nest of eggs that may have belonged to Protoceratops. Henry Fairfield Osborn thought the animal may have died while eating the eggs in the nest; perhaps it had been killed by an angry Protoceratops parent.
This possible diet of eggs led Osborn to name the genus and species Oviraptor philoceratops, which means "egg plunderer, lover of ceratopsians." At first Oviraptor was thought to be a member of the Ornithomimidae, but its fingers were not the same length and they ended in strongly curved claws. The ornithomimids had fingers about the same length and almost straight claws.
The skull of Oviraptor was short with large eye sockets, a crest above the snout, and a deep lower jaw with a large fenestra (opening) in the middle. Like the ornithomimids, both the upper and lower jaws were beaklike and toothless. The crest was full of sinuses, or cavities, which were filled with air when it was alive. The unusual jaws show that the animal had a specialized diet. Unlike most theropods, except the ornithomimids, Oviraptor and other members of the family Caenagnathidae were probably herbivorous (plant-eaters).
Recently discovered specimens show that aside from the skull, Oviraptor was similar to other theropods. An adult was about three feet tall at the shoulder and about six feet long from its nose to the tip of its tail. Its hands were moderately long, and the animal could use them to grasp. The long back legs show it had been a good runner. With no teeth, running may have been its only defense against other theropods.
Since the original specimen was discovered, several other skulls with skeletons have been found. These new specimens show that the size of the crest on each animal was different. The crest ranges from almost none to large. These differences are probably because of the different ages of the animals. This is supported by the fact that the small, nearly crestless forms had relatively large eye sockets while the large-crested forms had relatively small eye sockets. In many modern animals the size of the eye socket in proportion to the rest of the head gets smaller as the animal gets older, so the same may have been true for dinosaurs.
Oviraptor was closely related to Caenagnathus, from Alberta. Other relatives of Oviraptor were Chirostenotes and Elmisaurus.