[Taxacom] Two kinds of nictitating membranes

[Kenneth Kinman]

Hi Karl,    
      If it is an underlying synapomorphy, I would expect it to show up
somewhere among the actinopterygian fish (a huge clade that split off
between them).  If not, then I would not be inclined to call it an
underlying synapomorphy.  Of course, first we have to establish that
these are actually homologous structures.
          ------Ken Kinman

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Karl Magnacca wrote:                    
On Mon, March 23, 2009 3:09 pm, Kenneth Kinman wrote: 
> (2) Are the tetrapod and shark types homologous structures >(sort of a 
> distant parallelism) 
Dare we say, an underlying synapomorphy??? 
Karl