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Re: Ichthyornis paper



Christopher Taylor (ck.taylor@auckland.ac.nz) wrote:

<Also hidden in the paper is the coining of the name 'Pangalliformes' for
the total group of Galliformes. The reason given for the coining is that
'It is proposed here for increased precision, as one of the fossils
addressed in this document would be Pangalliformes incertae sedis but
there is no evidence that it is part of the galliform crown clade'.
However, as far as I can see from a brief skim of the paper (so I may be
missing something), there is nothing to directly say that it is *not* part
of the crown. In such a case, I personally would have preferred to call it
'Galliformes incertae sedis' and so avoid making a whole new name to keep
track of (I'm potentially distinguishing between 'incertae sedis'
[uncertain position in the clade, and/or potentially not part of it] and
'sedis mutabilis' [uncertain position within the clade, but definitely
part of it]). What do others think about this? Economy of taxon names, or
maximum precision?>

  Pan-stem clades do not correspond to clades that include uncertain or
"mutable" species, as implied, but are used as an approximation of the
living stem or node group, and ALL of its descendants. I tried to answer
the mystery of the pan-stem way back when:

  http://dml.cmnh.org/2004Jun/msg00033.html

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


                
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