Re: was: Wukongopterus and Darwinopterus now: cladistics.

[Mike Habib <habib@jhmi.edu>]

On Nov 30, 2009, at 11:59 AM, David Peters wrote:

> M. Habib wrote:
>
> Several robust studies indicate that this dichotomy does not work  
> very well in many circumstances.  I can provide specific citations  
> if need be, but a quick browse of Systematic Biology or Cladistics  
> will provide several examples.
>
> > >
>
>
> This sounds like a sledge hammer to the underpinnings of cladistic  
> analysis. One concrete example would be most helpful. Take your time.

Hardly - it simply means that purely dichotomous systems are often  
inadequate.  Other types of codings include things like multi-state  
characters, ordered characters, and continuous characters.  See:  
Pimentcl and Riggins, 2008; Jenner, 2002; Rouse & Fauchald, 1997;  
Rouse, 2001; Strong & Lipscomb, 1999; Forey & Kitching, 2000; Hawkins  
et al., 1997; Hawkins, 2000

> Turtles ancestors had temporal fenestra? Which is the ancestor with  
> fenestra that your are thinking of?

Many recent phylogenies place turtles somewhere within Diapsida  
(deBraga & Rieppel, 1996, 1997; Rieppel & Reisz, 1999; Hedges &  
Poling, 1999; Mannen & Li, 1999).  In such trees, the lack of fenestra  
in turtles is recovered as a reversal.

Cheers,

--Mike H.


Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
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mhabib@chatham.edu
(443) 280-0181