Re: Status of _Caudipteryx_

[Ronald Orenstein <ornstn@home.com>]

At 10:27 AM 30/12/00 -0500, ELurio@aol.com wrote:
> Well, it isn't EXACTLY "flightless, full-stop,"(it can glide, which is sort
> of flying) but that's not the point at all. Caudipteryx and some of it's
> contemporaries may NOT be "secondarily" flightless, but be the evolutionary
> equivilent of the colugo as compared to the fruit bat. The critters of the
> time we're talking about were more diverse than we currently know about.

This makes very little sense to me.  Are you suggesting Caudipteryx was a 
glider?  It seems most unlikely.  If you are suggesting that Caudipteryx 
and birds share a common ancestor but are not part of the same clade, then 
I guess it is a fair comparison (though so would "a human being as compared 
to a fruit bat").  I don't think anyone is proposing that Caudipteryx is 
the closest thing to a true bird that isn't one (that is, I suppose, its 
most immediate sister-group); the two competing theories seem to be that 
either it is a basal oviraptorid or a secondarily flightless bird (with the 
note that some think oviraptors are secondarily flightless birds, too).

As far as flightlessness is concerned, either Caudipteryx evolved from a 
flying ancestor or it didn't, but if it is a true bird it would almost HAVE 
to be secondarily flightless by definition if birds are defined as 
everything sharing a common ancestor with a living bird and Archaeopteryx, 
because that common ancestor surely had at least some ability to fly.  If 
it is NOT a true bird, then it could be secondarily flightless or not, 
depending on whether (a) there were ever any flying non-avian dinosaurs and 
(b) whether Caudipteryx evolved from one of them.  And that is a question 
we can't answer (at least not yet!).


--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
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