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RE: FEATHERS FOR T-REX?
T. Mike Keesey wrote:
> >To put it another way, possession of feathery integumentary
> >structures is *minimally* primitive for the Maniraptoriformes (if
> >_Sinosauropteryx_ is a basal maniraptoriform).
>
>Kind of a big assumption, isn't it? I would say it's minimally primitive
>for Clade(_Sinosauropteryx prima_ + _Vultur gryphus_).
This is kind of what I meant. I used the name "Maniraptoriformes" for this
clade; I know it isn't the definition, but it approximates the content. In
which case, it isn't a big assumption - although, perhaps a minor
assumption, since it assumes that _Sinosauropteryx prima_ is a basal
maniraptoriform.
In any case, I think we may be splitting hairs (or protofeathers) here. The
alvarezsaurids may lie closer to the base of the Maniraptoriformes than
_Sinosauropteryx_, in which case _Shuvuuia_ is the most basal theropod to
show feather-like integumentary structures. In this case, the possession of
feather-like integument is minimally primitive
for Clade (_Shuvuuia deserti_ + _Vultur gryphus_). According to Xu et al.
(2002), Tyrannosauridae lies outside this clade. Close, but no cigar.
(By the way, I've seen "Shuvuuia mongoliensis" written in the Ostrom
Symposium volume; I'm assuming it's a misspelling of _Shuvuuia deserti_).
>Whether certain
>clades (_Tyrannosauroidea_, _Ornithomimosauria_, etc.) belong to that
>clade or not is currently unresolved.
Depends which paper you consult, I guess. I used the phylogeny in the
_Sinovenator_ paper.
Tim
------------------------------------------------------------
Timothy J. Williams
USDA-ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014
Phone: 515 294 9233
Fax: 515 294 3163