Caudipteryx - Classification

Classification

The consensus view, based on several cladistic analyses, is that Caudipteryx is a basal (primitive) member of the Oviraptoridae, and the oviraptorids are nonavian theropod dinosaurs. Incisivosaurus is the only oviraptorid that is more primitive.

Halszka Osmólska et al. (2004) ran a cladistic analysis that came to a different conclusion. They found that the most birdlike features of oviraptorids actually place the whole clade within Aves itself, meaning that Caudipteryx is both an oviraptorid and a bird. In their analysis, birds evolved from more primitive theropods, and one lineage of birds became flightless, re-evolved some primitive features, and gave rise to the oviraptorids. This analyis was persuasive enough to be included in paleontological textbooks like Benton's Vertebrate Paleontology (2005). The view that Caudipteryx was secondarily flightless is also preferred by Gregory S. Paul, Lü et al., and Maryańska et al.

Others, such as Stephen Czerkas and Larry Martin have concluded that Caudipteryx is not a theropod dinosaur at all. They believe that Caudipteryx, like all maniraptorans, is a flightless bird, and that birds evolved from non-dinosaurian archosaurs.