Oviraptorosauria

Oviraptorosauria is a clade of feathered theropod dinosaurs within the broader group of maniraptorans, known from the Cretaceous period. The fossil record spans roughly 125 to 66 million years ago, with most finds coming from Asia (notably Mongolia and China) and North America. The group includes small to medium-sized dinosaurs that occupied a variety of ecological niches during the Late Jurassic to Late Cretaceous.

In terms of anatomy, oviraptorosaurs typically have short, high skulls with beaked mouths and a mix of toothless and toothed jaws. Many display crests or other ornamentation on the skull, and they possess stout bodies with relatively strong forelimbs. Limb proportions and tail structure vary among taxa, but overall they are characterized by a beaked snout and a generally bird-like, two-legged stance.

Taxonomically, the clade is divided into two main families: Oviraptoridae and Caenagnathidae. Oviraptorids, such as Oviraptor, Citipati, and Khaan, tend to have robust skulls and distinctive crests, while caenagnathids (including genera such as Anzu and Elmisaurus) often show longer snouts and more elongated skulls. The exact relationships among oviraptorosaurs remain a topic of ongoing research, and some analyses recognize additional subgroupings within these families.

Ecology and behavior evidence suggests a varied diet, likely including plants, small animals, and possibly eggs, aided by their beaks and jaw structure. Notably, several oviraptorosaurs are known from nesting sites, and some specimens show postures interpreted as parental care, indicating complex reproductive behavior similar in some respects to birds.

Oviraptorosaurs are important for understanding the diversity of beaked theropods and the evolution of feeding strategies and reproduction within later theropods and early birds.