Re: Mononykus

[tlford@ix.netcom.com (Tracy Ford)]

You wrote: 
>
>        Note that I meant (and I understand that this was unclear) 
"ossified
>(in adults) keel" on an "ossified (in adults) sternum". Clearly, the 
sternum
>is primitive for Archosauria. The ossified keel is derived. Whether a
>cartilagenous [sic?] keel was present in most theropods may be 
unknowable.
>        Since the current distribution of that character is confined 
to "the
>'headless' wonder", _Mononykus_, and various ornithothoracine birds
>(assuming mony isn't one), and other charcters presumably suggest that 
"the
>'headless' wonder" is not a bird (sorry, George, as scientists, we 
must
>proceed from the hypothesis which best fits the evidence; "BCF" does 
not),
>then the ossification of the sternal keel is most likely to have 
happened at
>least twice.
>  

And what if the sternum of Mononykus isn't a sternum? What then?

Tracy