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Re: was: Wukongopterus and Darwinopterus now: cladistics.



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
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181