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Re: Ostrom Symposium - Part 2



 ornstn@home.com wrote:


> at least I
> didn't ask <snip> why flying birds hadn't lost their legs altogether
<which was Ostrom's question to a speaker>

Because 99.9% of the time, when they landed on the ground they would tip
over.  Of course the other 0.1% of the time, they might get lucky and
land close enough to an object to lean on so they wouldn't tip over in
front of on-looking birds.  So the answers to Ostrom's question are:
"Peer-pressure to not  tip-over", and also "fear of embarassment".


> In one of
> his few concessions to the general flow of opinion, he did agree that
> alvarezsaurids are most like ornithomimids.


It wasn't that much of a concession. Martin was among the first to posit
this at an SVP meeting a few years ago (in fact, he may have been the
first).  Larry was probably smiling as he said it.


> Currie pointed out the similarity between the "halo" effect of the
> feathers of Confuciusornis and the integumentary structures (whatever
they
> are) of Sinosauropteryx - noting that nobody has questioned the
identity of
> the former, though they have not been subjected to close scrutiny!

In fairness to the "healthy-skepticism" side, it should be pointed-out
that the null hypothesis for Confuciusornis is that it *had* feathers,
because it is the most parsimonious explaination (because it *is* a
bird).  The null hypothesis for Sinosauropteryx *was* that it doesn't
have feathers/"proto-feathers" (the "null" seems to be rapidly
unravelling....but I'm still waiting for someone to publish SEMs of the
fibers).  I would also like to see an attempt at a life-reconstruction
drawing of one of those structures (similar to what has been done many
times for the conodont animal's mouth-parts complex).  So far, there are
too many words, and not enough illustrations.  Or, as Mr. Burns (of
"The Simpsons") once said, "To much dancing, and not enough prancing!"

 > He <Phil Currie> showed slides indicating that
> these structures appear thicker at the base, with longer and thinner
ones
> extending further out, a condition that also seems to prevail in
> Protarchaeopteryx.  Currie interprets this as representing a thick
base
> breaking up into a distal plumulaceous portion, indicating a simple
> branching structure - though I am not sure I saw this in the slides.

We need SEMs!


> In short, neither Caudipteryx nor Protarchaeopteryx fall
> within the Avialae.

(as <pb> does a little dance).  So I gather from other posts, all
experts (except Martin, of course) that attended seemed to agree that
Caudi' is a basal oviraptorosaur of some sort?  Hot doggies.  Last I
heard (just after Norell et. al's paper came out last year), Caudi' was
probably in Avialae (even though Norell et al. figured it as being
outside of Avialae), and Protarchie' was "floating" somewhere between
the dromaeosaurs (close sister group?) and Avialae.  Has Protarchie's
position been better established yet?

                          <pb>