The earlist known caenagnathid. Oviraptorosaurs include the more poorly known Caenagnathidae, specimens of which consist mostly of lower jaws that were initially assigned to birds (Sternberg, 1940; Cracraft,1971) Osmolska, 1976 recognized similarities with Oviraptor and correctly referred the Caenagnathidae to the Theropoda. 

Mandibles of oviraptors and caenagnathids are similar in the peculiar structure of the artucular, in their toothlessness, in the size of the ecternal mandibular fenestra, and in general outline. However, an oviraptorid jaw has a relatively larger external mandibular fenestra, a more highly arched dentary, a more prominent coronoid process, and a more pronounced concave outline posterior to the back. Caenagnathasia  lived 5 million years earlier than Chirostenotes / Caenagnathus and was much smaller. As in oviraptors the braincase is highley pneumatized, although the bassal tubera and basispterygoid processes are aligned vertically (Sues, 1994)