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Re: FEATHERS FOR T-REX?



David Marjanovic (david.marjanovic@gmx.at) wrote:

<I hope Arctometatarsalia was defined later than Ornithomimosauria.
Anyway, I think care will be taken to produce this situation -- that, if
Arctometatarsalia is a synonym of Ornithomimosauria, it is a _junior_
synonym -- will be replicated under PhyloCode (remember: PhyloCode won't
be retroactive and will reset all priority of definition to zero). That
chance is probably smaller for Carnosauria, but at least it's defined so
that *Allosaurus*, _the_ carnosaur, always is a carnosaur; though I do
think Allosauroidea or even Allosauria look better.>

  Ornithomimosauria has, as far as I can tell, been defined as
{*Ornithomimus* > *Troodon*}, by Holtz, in accordance with the
Bullatosauria hypothesis. This gives the taxon a lesser subjective use
than Arctometatarsalia in some hypotheses. Problematically, Sereno defined
(1999) Ornithomimidae {*Ornithomimus* + *Pelecanimimus*}, ignoring
Ornithomimosauria, and including Alvarezsauridae in his Ornithomimoidea
{*Ornithomimus* + *Mononykus*}. This makes the two clades,
Arctometatarsalia and Ornithomimosauria, with close to the same content
... but they are still separate taxa. I would _add_ exclusive anchors, to
further clarify Holtz' definition, or he may, but for now, they are
different definitions.

  Oh, for the record, the definition may in fact be explicit to the
Bullatosauria, and thus would only hold true if Bullatosauria was a found 
grouping. This may make the definition void, and prompt a newer
definition. Sereno's definition may then show that _Ornithomimidae_ has a
greater content than any supportable definition for _Ornithomimosauria_
unless someone gets inventive.

=====
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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