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re: Pterosaur wings and refs



David Unwin wrote:
>>With regard to wing shape in pterosaurs. I have seen direct evidence
of
brachiopatagium attachment to the hind limb, as far as the ankle, in
Sordes,
Rhamphorhynchus, Pterodactylus and what is probably Tapejara. <<

David, I don't doubt that you saw what you saw, but that's the power of
the paradigm.
I will be able to better respond to your points after the paper is out,
so this will have to be my last post on the subject until then. For now,
I can tell you that the first three pteros you mentioned will be covered
in the paper. The last I am not aware of, but if anyone has a jpg, I'd
be interested.

>> I have also seen
very good photographs of specimens of Eosipterus (the specimen described
by Lü
2002) and Jeholopterus that also appear to show exactly the same thing.

Not aware of the Eosipterus specimen. Jeholopterus figures big in the
paper though. Again, send a jpg, something I can bat against. Not just
words. This could be fun.

>> So, the
same relationship seems to be present in six different pterosaurs
representing
at least four completely distinct major clades. Add to this Hazlehurst's
(1991)
discovery of a good correlation between fore and hind limb length in
pterosaurs,

This is probably true because in a balanced standing bipedal pose the
distal metacarpus of nearly all pterosaurs will touch the ground, or at
least the ankle, by simple elbow extension (short-armed Austriadactylus
and Campylognathoides zitteli are the sole exceptions). Thus pteros were
able quadrupeds and bipeds, _even better_ than the frilled lizard and
her 18 extant sisters who can morph in moments from a cold-blooded
undulating quad into a speedy, digitigrade biped. I can send Internet
links to mpg movies of same if interested.

>>the general similarity of appendicular morphology across a wide
range of taxa, including all those with direct evidence of
brachiopatagium
attachment to the hind limbs, and one ends up with a clear, well
integrated
picture of whats going on in pterosaurs vis a vis wings and legs. Note
that
this 'Sordes' model is also completely consistent with, for example, qu!

adrupedal plantigrady - as shown y thousands of pterosaur tracks, and is

supported by a new study by Matt Wilkinson (Cambridge) showing how
effective
and aerodynamically advantageous wing attachment to the hind limbs was
for
pterosaur flight. Since no one has ever presented any evidence, direct
or
indirect to show that the brachiopatagium was not attached to the hind
limb, in
any pterosaur,

Just a few more weeks you'll have it.
I thought of you, David, often will writing the paper.
Fasten your seatbelt. You're in for a paradigm shift.

>> it is most parsimonous to assume that the Sordes model, at least
with respect to the brachiopatagium, applies to all pterosaurs.

You'll be surprised how quickly and how well the traditional Sordes
model falls apart. I found something you and Sharov missed.

>>Reconstructing,
the exact shape of the brachopatagium, as it was in life, is more
problematic
in that its not clear how extensible it might have been originally.
Certainly
what is evident in fossils should probably be taken as the minimum.

In my opinion, what is evident in fossils should probably be taken as
is. By the way, next to Jeholopterus, Sordes, the holotype, provides the
best current example of a narrow chord wing.

Until then ~
David Peters