Oviraptorids are currently known only from the Late Cretaceous of Asia, with the most well-known species and complete specimens found only in the Gobi Desert of Mongolia and northwestern China.

Some phylogenetic studies have shown that Oviraptor is the most primitive known oviraptorid, thus making Citipati a closer relative of the "ingeniines" and this traditional division into crestless and crested forms artificial.

[2] Other possible oviraptorids include Nomingia gobiensis, Gigantoraptor erlianensis, Jiangxisaurus ganzhouensis and Shixinggia oblita.

However, according to Mickey Mortimer, the clade can be considered valid because its describers explicitly name it as new, which satisfies ICZN Article 16.1.

[4] Nankangia Oviraptor Yulong Wulatelong Rinchenia Tongtianlong Ganzhousaurus Citipati Zamyn Khondt oviraptorid Huanansaurus Corythoraptor Shixinggia Khaan Conchoraptor Machairasaurus Nemegtomaia Heyuannia huangi Heyuannia yanshini Banji Jiangxisaurus Oksoko The diet of oviraptorids is not fully understood.

[5] Originally, oviraptorids were thought to be specialized egg raiders, based on a Mongolian find showing Oviraptor on top of a nest erroneously attributed to the ceratopsian dinosaur Protoceratops.

In contrast, the jaws of oviraptorids had thin, sharp edges probably supporting shearing beaks, ill-suited for cracking shells.

[7] Evidence of partial carnivory among some oviraptorines comes from a lizard skeleton preserved in the body cavity of the type specimen of Oviraptor[8] and two hatchling Byronosaurus skulls found in a Citipati nest.

This behavior is supported by the fact that the eggs oval shape, with the more narrow end pointing backward from the birth canal, matching their orientation toward the center of the nest after being laid.

[14] The presence of two shelled eggs within the birth canal shows that oviraptorosaurs were intermediate between the reproductive biology of crocodilians and modern birds.

[14] In 2017, paleontologists discovered colored pigments in some fossilized oviraptorid embryos of the egg-shell genus Macroolithus (which may represent eggs of Heyuannia).

[15] A study by Robert Eagle et al. of the University of California-Los Angeles indicates that from specimens of eggs found in Mongolia and examination of the isotopes carbon-13 and oxygen 18 found within, Oviraptorids had body temperatures that could be elevated higher than that of the surrounding environment but lower than that of birds.

[20] The brooding oviraptorid specimen IGM 100/979 showed a callus and possible longitudinal groove left over from a healed fracture of the right ulna.

The same pattern holds true for protoceratopsids, indicating that both groups preferred dry, desert-like habitat, and fed mainly on the types of tough, low-growing plant life that grows in arid climates.