Re: Propatagium reveals flying ancestry of oviraptorosaurs (new Feduccia & Czerkas paper)

[Tim Williams <tijawi@gmail.com>]

Mickey Mortimer <mickey_mortimer111@msn.com> wrote:

> The context of the abstract makes it pretty clear the authors mean aerial 
> habits instead of powered flight,
> since they contrast it with terrestriality.


The entire paper (including the title) make it clear that they regard
_Caudipteryx_ as secondarily flightless ('neoflightless').  The
authors differentiate 'gliding', 'volant' and 'neoflightless'.


The authors also compare non-volant oviraptorosaurs favorably to
ratites, and regard oviraptorosaurs as terrestrial, secondarily
flightless birds.  There's not a lot of nuance in what they mean by
"volant" - they mean powered flight.  ("The presence of numerous
flight features reveal that Caudipteryx, like the extant flightless
ratites, originated from volant ancestors..." and so on, throughout
the paper).


> Also, would you really say there's been a consensus oviraptorosaurs were 
> secondarily terrestrial?


No, I wouldn't.  Personally, I don't believe it.  I think all
theropods stemward of Pygostylia were *primitively* terrestrial, with
little (if any) arboreal abilities.


> I know Paul's believed it, as have I since 1998, but I'd say there are plenty 
> of paleontologists who have
> proposed Caudipteryx's wings evolved in a terrestrial setting, for display, 
> brooding, running up inclines,
> etc..


Broadly, I'd go along with that.  _Caudipteryx_ is perhaps not a good
example of non-flight aerial behaviors, because its forelimbs were so
short (probably, although not certainly, secondarily reduced).  But I
subscribe to the hypothesis that flight evolved in theropods that were
terrestrial ("ground-dwelling"), as opposed to arboreal (spending most
or all of their time in trees).


I should add that I'm skeptical of the reported preservation of a
propatagium in _Caudipteryx_... but that's another issue.





Cheers
Tim