Oviraptoridae

Lore & Background

Oviraptorids are known for their distinctive skull structure, including short snouts, deep mandibles, and in some taxa such as Citipati, Corythoraptor, and Rinchenia, a midline crest resembling that of a cassowary. Their jaws were edentulous, with two small bony projections on the roof of the mouth. The classification of oviraptorids has been controversial, with studies dividing oviraptorosaurs into Caenagnathidae and Oviraptoridae, though some phylogenetic work suggests traditional members of Caenagnathidae may be more closely related to crested oviraptorids. The Oviraptoridae itself is traditionally split into the small, short-armed, mainly crestless Heyuanniinae and the larger, crested, long-armed Oviraptorinae, but some studies consider this division artificial.

Reader's Guide

Oviraptoridae are significant for their bird-like features and the light they shed on theropod reproduction and behavior. Originally thought to be specialized egg thieves based on a find of Oviraptor atop a nest attributed to Protoceratops, later discoveries of Citipati specimens brooding the same types of nests and a Citipati embryo inside such eggs corrected this error. Their diet remains debated: while some evidence suggests partial carnivory (a lizard skeleton in Oviraptor and hatchling Byronosaurus skulls in a Citipati nest), their beaks most closely resemble those of herbivorous dicynodonts, parrots, and tortoises. Oviraptorid eggs are well known, found in nests arranged in concentric circles, with brooding postures identical to modern birds. A specimen with two unlaid eggs in the pelvic canal indicates they produced eggs in pairs, intermediate between crocodilian and avian reproductive biology. The discovery of Baby Yingliang, a well-preserved embryo in a tucked posture similar to extant birds, further links non-avian dinosaurs to birds, though this interpretation has been challenged.

Did You Know?

• Oviraptorids were originally thought to be specialized egg thieves, but later discoveries showed they were brooding their own eggs.
• Some oviraptorids had midline crests on top of the skull resembling those of cassowaries.
• Oviraptorid eggs are shaped like elongated ovals and resemble the eggs of ratite birds such as ostriches.
• A specimen with two unlaid eggs in the pelvic canal suggests oviraptorosaurs produced eggs in pairs, not all at once.