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Re: back to pteros, [yada, yada]

----- Original Message -----
From: "Jaime A. Headden" <qilongia@yahoo.com>
Cc: "david peters" <davidrpeters@earthlink.net>
Sent: Wednesday, August 03, 2005 10:21 AM

As for identifying it
as an anuorgnathid -- my argument about this is the methods used to support the
ID, rather than the ID itself. In Peters' words:

"I employed the usual techniques and started tracing the contours of the
bones. I found teeth right away, but not where Wang and Zhou said they would
be. And I did not find teeth where they reported two to be.

In the latter case why don't you trust Wang & Zhou? Tooth enamel is very difficult to confuse with anything else. They had the specimen in their hands, and I can't imagine anyone would mistake bone or anything for enamel under such conditions.

And the drawing of lines on a slab perceiving that the completely prepared
matrix in a chalk bedding plane described "hidden" bones? This was the case for
another published objection to this technique on the basis of *Nyctosaurus* sp.
Since the slab itself was prepared down to recover bones within the chalk, it
is impossible for impressions of bones or tissues to be preserved out of the
bedding plane recovered.

Yeah, that was rather embarrassing... it is good evidence that the technique consists mostly of treating a slab of rock as a Rorschach test.

<The beauty of this technique is that you can add a layer to pinpoint errors
and you never have to _believe_ a line drawing again! I once sent an image of a
pterosaur rostrum to a colleague and showed him where to find the naris 'that
shouldn't be there'. He responded by saying that all he saw was 'a hole in the
rostrum with matrix coming through'. I said, that's the naris! He wouldn't
believe his own eyes.>

Yes, if I find a crack in the bone and the bone is flaked out (like what
happens when bone is either eroded or removed during splitting of a slab) it
will look like a "naris" too.

Thanks for reminding me! All sorts of _horrible_ things happen when a slab is split. That's why the best specimens (like the *Confuciusornis* exhibited in the museum in Vienna) come out of slabs that have not been split. Commonly the bones are split right through the middle. *Aberratiodontus* seems to lack any exposed bone surface -- that's why I didn't enter it in my matrix; I was too frustrated at the impossibility to determine the presence or absence of just about any process on any bone.

It's certainly common that a flake of a thin bone breaks away with the counterslab, leaving a hole in the rest of the bone that breaks away with the slab.

Such subtleties are the very basis of the contention. A missing flake of bone
in the snout of a pterosaur is not the same as a whole skeleton of
*Longisquama* on the holotype slab as Dave contends. Dave has argued from a
developmental standpoint that the bones of many babies and even "adults" are
present, form impressions, or never ossify, contrary to any developmental model
thus far known.

Plus, contrary to what we know on the _mechanical_ properties of cartilage. Try to fly with wing "bones" that are no stiffer than the thinner parts of your ears!

http://www.fhsu.edu/biology/cbennett/critique.html 

Whew... wow.

Let's have a look at fig. 2. I see teeth there -- except they are colored violet as belonging to the left maxilla. In fig. 5 they don't look any different from the real teeth. Why doesn't anyone interpret them as teeth? Why does the "left maxilla" extend sweepingly over those pointed "elements" that are not connected in any visible way in fig. 2, 3 or 4.

Then the big blue area labeled as the frontal. It is obvious in fig. 12, fig. 6 and even fig. 5 that is is merely the matrix _between_ two bones which happen to lie in such a configuration that they approximate the shape of the orbital margins of a pair (!) of frontals.

Within the "frontal" there is a line which supports three "teeth" (shorter and more recurved than the other ones, including those I have "found" above). If that line wouldn't end blind on both ends, I'm sure it would have been interpreted as a jaw margin.

Then there's the descreening. This is self-deception marked not with a red flag but with the full attributes of a police car. (An Italian one that sounds like Tarzan: AWWWWEEAWEEAWWWWEEAWEEAWWWWEEAWEEAWWWW...) Descreening creates information that never existed in the photo! The pixels are not a pattern that overlies the image, which is how descreening treats them. They _ARE_ the image. Enlarging such a low-resolution picture to the point that the pixels attain millimeter size is a null magnification. It doesn't show _anything_ that isn't visible in the printed encyclopedia.

<How can you expect to discover anything new if you don't stick your neck out
once in awhile? I'm not afraid of making errors (obviously). Every error brings
one closer to the truth. Isn't that what it's all about?>

Yep, but I get the feeling that when we here try to point out your errors, you more or less ignore us and try to publish them anyway, with the only result that you and the peer-reviewers annoy each other.

I know that you have successfully published some of your ideas. I admire your Historical Biology paper on the origin of the pterosaur wing "with a twist". It doesn't involve photointerpretation or a phylogenetic analysis riddled with size- and/or ontogeny-related characters, and thereby shows that you can do good science.