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RE: FEATHERS FOR T-REX?



Doc Tom Holtz (tholtz@geol.umd.edu) wrote:

<To add a third definition, Padian, Hutchinson & Holtz (1999) used the
version "all descendants of the most recent common ancestor of
_Ornithomimus_ and _Pelecanimimus_", making a node-based Ornithomimosauria
within the stem-based Arctometatarsalia.>

  Ah, shoot ... should have checked that reference.

  This only begs the question ... what definition and reference taxon
should be used? Applying principles of priority, it would be Holtz (1994).
Applying to concepts of present organization, Padian et al. (1999) would
be considered "appropriate" except in reference to priority. I know
arguments against Sereno (1999) go without saying, as the taxa were
defined in organization of a radical phylogeny that is supported by no
other coelurosaur researchers. Ornithomimidae has not, I beleive, been
otherwise phylogenetically defined.

  Arctometatarsalia = {*Ornithomimus* > Neornithes} Holtz, 1994
  Ornithomimosauria = {*Ornithomimus* > *Troodon* in Bullatosauria} Holtz,
    1994
  Ornithomimidae = {*Ornithomimus* + *Pelecanimimus*} Sereno, 1999
  Ornithomimosauria = {*Ornithomimus* + *Pelecanimimus*} Padian,
    Hutchinson, & Holtz, 1999

=====
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.

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