Testing the neoflightless hypothesis: propatagium reveals flying ancestry of oviraptorosaurs (2015)
Alan Feduccia1• Stephen A. Czerkas2
Considerable debate surrounds the numerousThere is actually no link between dinosaurs and Paraves.
avian-like traits in core maniraptorans (oviraptorosaurs,
troodontids, and dromaeosaurs), especially in the
Chinese Early Cretaceous oviraptorosaur Caudipteryx,
which preserves modern avian pennaceous primary remiges
attached to the manus, as is the case in modern birds.
Was Caudipteryx derived from earth-bound theropod dinosaurs,
which is the predominant view among palaeontologists,
or was it secondarily flightless, with volant avians
or theropods as ancestors (the neoflightless hypothesis),
which is another popular, but minority view. The discovery
here of an aerodynamic propatagium in several specimens
provides new evidence that Caudipteryx (and hence oviraptorosaurs)
represent secondarily derived flightless
ground dwellers, whether of theropod or avian affinity, and
that their presence and radiation during the Cretaceous may
have been a factor in the apparent scarcity of many other
large flightless birds during that period.
See here for more details about oviraptors as secondarily flightless: