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Re: Important feathered dinosaurs
Larry Febo wrote:
<OK. Perhaps the nodes are questionable. What about
the triosseal canal? ...the large keeled sternum?? It
seems that the majority don`t see it as being avian,
but then,...what is it? I haven`t heard any alternate
proposals put forward as to what it could possibly
Okay, I've been reserving judgement on *Protoavis*
for some time, and will continue to do so until
whatever analysis is published that allows us to see
photos of the original, as in Norell et al.s various
papers in AMNovitates and elsewhere with interpretive
But I have seen some of these features, and can
comment on Larry's comment. First, in birds, quill
nodes are found on the ulna, not on the metacarpals,
as far as I can tell; in addition, these appear to be
ridges, not just "bumps". The appearance of "nodes" on
the proposed second and third mcs in *Protoavis* would
depend on the simple mound-shaped nodes, rather than
ridges, but they _could_ support structures, or
rigidify the manus (or foot, as Holtz suggests).
However, keeled sterna, if it is indeed that in
*Protoavis*, are present in many non-avian flying
forms, such as advanced bats (not *Icaronycteris*,
etc.) and also in non-maniraptoran theropods
(*Sinraptor*), but not in pterosaurs or
*Archaeopteryx* for the most part (excluding *A.
bavarica*, which has it), suggesting that, though
while birds need it to fly, the actual function is
much, much more simple, and mainly provides a greater
surface for attachment of the pectoralis muscle,
instead of widening the sterna, which expands the
chest and this can be counterproductive to use of this
muscle as it separates the arms further from each
refs: Carroll, 1988 [his Vert. Paleo. book], Wellhofer
(various) [Archie, pterosaurs, etc.] Currie and Zhao,
1995? [Sinraptor], Chatterjee, 1992 [his bird book].
Jaime "James" A. Headden
"Come the path that leads us to our fortune."
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