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Re: Wilkinson's new pterosaur paper, Cunningham, Habib
Are you _telling_ me about your evidence in Sordes??
Please, _show_ me.
At least Unwin and Sharov provide cartoons. But unfortunately they
didn't match on one wing, so what kind of confidence can we have in
Sordes does not defy my model. Rather it's a prime example. Since the
Historical Biology paper was published some 6 years ago, no one had
disputed it in print or elsewhere with evidence.
On Jul 13, 2007, at 12:45 PM, Jaime A. Headden wrote:
Dave Peters (firstname.lastname@example.org) wrote:
<My whole point is
1. strict unbiased observation (precise tracing);>
Tracing is biased, however, as it is based on perception of what
what. Viewing a slab and sampling the material is the only way to
KNOW what is
what on the slab. In the case of unpreserved membrane, in examples
*Sordes*, you have heavy carbonaceous remains on the slab that in
are not fully preserved. But you do not have ONE slab, you have
furthermore slabs are not all exposed or even buried in a single
plane, as has
been explained before rather more than a few times. Missing
material from just
behind the elbow can be solved by somewhat of a simple technique,
if there are
aktinofibrils which disappear before they reach the elbow, but
would seem to
extent to the elbow's "vanishing point". As these have been
hypothesized to be
evolved muscle tissue, I doubt they are NOT attached to the limb
itself in any
way, and perceiving an actual hole would tend to be viewed as a first
impression improbability that would require testing (and proof) to
about function from.
<2. reconstruction in all configurations (folded, open, partially
Moreover, reconstruction based on not artificially condensing the
the finger is extended, or considering the ability to lengthen the
the wing is in any shape, which the aktinofibrils suggest is
rotating the wing shape as preserved on the slab out and filling in
based on a perceived narrowness proves very little.
<3. interpretations must be supported by data (evidence).>
I wholeheartedly agree. See above. Practical experimentation and
examination a must in this field, however. A good deal of people
from Jim to
Conway to Unwin and Kellner are working on physical models under
to test aerodynamic shape and controls of wing planform and function.
<Just come up with a single specimen that does not follow the rule
and I will
grant you that variation in inboard wingshape can and does occur.>
I would throw the old standby out as evidence, but it would be
due to the same tracing "evidence" that has been used before, but
I'll do it
again: *Sordes pilosa* defies nearly all Peters' arguments about
save one: It can, in fact, have a narrow-chord wing that extends to
Jaime A. Headden
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
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