RE: Caudipteryx (was Re: Just following the trend of questioning. ..)

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

Mickey Mortimer wrote:

> As the only other coelurosaurs with two or less phalanges on digit 
> III are tyrannosaurids and derived pygostylians (Protopteryx, 
> Longipteryx, Eocathayornis, ornithothoracines), 

What about alvarezsaurids and carnotaurines?

> and there's no other evidence it's related to these clades, the reduced 
> third digit is just an apomorphy.  

Autapomorphic for _Caudipteryx_ - exactly.  It implies that _Caudipteryx_
achieved an effectively didactyl manus without loss of manual digits.
Considering the range of manual configurations seen across non-avian
Theropoda, any consolidation or loss of digits doesn't necessarily imply
secondary flightlessness.


Jaime Headden wrote:

> Problematically, caenagnathids (improp. elmisaurids) have broad
> interpahalngeal joints that would make this difficult, if not 
> impossible. This indicates a robust articulation, and this is even 
> more etxreme in *Elmisaurus rarus* than it is in any other taxon; in 
> fact, the ration between width of the distal and proximal ends and 
> the shaft width is diagnostic to the taxon so far.

I found this extremely interesting.  However, I don't see how this precludes
syndactyly in elmisaurids.




Tim