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re: Defending Photoshop






         With Longisquama you're dealing with a specimen that is covered
in _a lot_
         of skin.

Is there anything else than its position (which makes sense) and its
shape
(which makes at least some sense) that tells you that it _is_ skin,
rather
than (say) a couple of unconnected discolorations?


>>>> Okay. Sharov and others have noted dewlap scales. I've seen
brachiopatagia. You've all seen the plumes. Those are all from the
undisturbed upper torso, forelimb and head areas. Not completely
undisturbed, though, because the upper half has rotted and drifted
enough to dislodge both pectoral girdles and the complete sternal
complex, along with some ventral rib tips. If you've seen the PT article
or pterosaurinfo.com, which has the same image, as I recall, you'll note
that the lower belly has suffered the most dislocation, perhaps because
of belly gases? But also part of this area is covered by the
brachiopatagium. The legs have both rotated dorsally so that the toes
are near the former spine. As you'll remember from my cladogram
Longisquama comes between Sharovipteryx and pterosaurs, thus it no doubt
also had uropatagia. I haven't been able to trace the uropatagia in
Longsiquama. But the uropatagia that must be there may also be a culprit
in clouding things up. Just a logical conclusion. No real evidence. But
it stands to reason. Posterior to the hips, there's not much else. The
tail is attenuated. Other than that feeble explanation I can't tell you
why some bones are crystal clear and others are ephemeral. >>>>>>


         Much of the skin overlaps bones which makes them hard to see.
I've mapped
         out all the bones and skin boundaries and embryos I could
discern

Do you have any speculation on why the bones of the same articulated
skeleton are preserved in such different way -- some are smooth, hard,
and
have a different color than the matrix, while others look exactly like
the
matrix and are only discernible by their supposed shapes?

>>>> No. I just accept it for what it is. If what I saw was imaginary,
why wouldn't I draw it in some sort of preconceived fashion following
the imaginations of Sharov, Bakker and Hauboldt & Buffetaut who all drew
pretty much the same critter? Why didn't I draw the legs drifting off
the bottom of the rock? No for some reason what I found was symmetrical
even though not preserved in any obvious symmetrical fashion. It nested
neatly within a phylogenetic framework of established taxa. And it
spelled out in incredible detail how paedomorphosis made pterosaurs out
of baby longisquamids. And it was all overlooked data. You can't ask for
a better story, except that is ticks people off. >>>>>


         (and that means I had such a very hard time seeing some of them
that they
         only became recognizable _after_ the tracing was done). The
toes were seen
         before, but interpreted as subdivided plume shafts. The femur
was seen
         before but interpreted as plume going off in a different
direction than
         the rest of the plumes. So I was not the first to see these
structures. I
         only did the tight tracing that revealed how they were all
connected
         together.

So... have I understood this correctly? First you trace everything, then
you
look at your tracing and try to interpret it? If so, how is this
different
from a Rorschach test?

>>>>>>  A Rorsharch test starts with a piece of string and ink.
Somewhere on the Longisquama slab there were overlooked and overlapping
body parts. Unwin and Benton had a good look at it. I can only wonder
why the didn't put pencil to paper, rather than just type out their
confirmations and questions of Sharov's original observations. They had
it in their hands and they let it slip through their fingers. Almost
like an Indiana Jones story, they did not recognize the Holy Grail when
they were looking at it. >>>>>>>


         It would be nice if someone could duplicate the method (so far
no one has
         sent me tracings for
approval/verification/condemnation/whatever).

I hope to have demonstrated that the method can lead to dramatically
erroneous results... it would be nice if someone would criticize my
tracings. Nobody has done that so far.

>>>> Send a nice 4  to 10 Mb file to dpeters@kupperparker.com where the
modem is faster.>>>>>


(I need to find the tracing where I found a tritylodontid jaw or at
least
bite mark. That file is not where it should be.)


         Some of those little soft bone pterosaurs I was seeing turned
out to be
         [possibly] pre-shell embryos, now possible in the pterosaurs as
lizards
         scenario. It could be that they only wore the shell for hours
or days.

You mean they were in utero, in eggs that would have been shelled and
laid
later?

>>> I think so. That seems to fit the rest of the story.  They aren't
archosaurs, that's for sure. >>>>>


         But in the meantime, isn't it nice to know that what starts off
as jumbled
         tracings of ephemera pull together to create a series of
morphologies that
         make sense? That resemble one another? That provide antecedence
and reason
         for various bizarre structures that come later?


A good just-so story, a coherent picture, is not evidence. It is the
result of evidence -- or not.

>>>>> Alls well that ends well.  Still it answers more questions than
Wild's colugosaurus. >>>>>>>


         Don't knock the technique or the interpreter. Knock the
interpretation.


Don't knock the interpreter. Knock the technique. If you can't knock the
technique, _then_ knock the interpretation.

>>>> You're like knocking pen and pencil when they skip details. Not
right. >>>>>>




         PS More dust will be raised with my interpretation of the
skull  of
         Sharovipteryx. Just remember that every other bone in this
specimen was
         preserved in place and undisturbed. And no one else has even
attempted to
         update Sharov 1971. That makes nearly 35 years that this
treasure has lain
         dormant.


I agree it should be revised by someone -- by someone who has actually
studied the fossil under a stereo microscope. Even then I don't think
the
two-dimensional skull will provide much information.

>>> Actually your wish is coming true, somewhere else. >>>>>>


         Did I mention there are two ant/wasp-like insects preserved in
         the skull? That's how good preservation is.


How do they look like ants or wasps? To me they look like stylized
beetles -- or like ostracod shells, which must be expected anyway in a
freshwater lake like that, and are hard enough to fossilize easily. No
legs or wings are visible in your photos (...except if the left and
right
"ostracod shells" turn out to be beetle elytrae).

>>> There are beetles galore outside the fossils. Two little
ant/wasp/bees/ whatever inside. Turned to stone. The legs are harder to
see. And once again, it's an interpretation. Knock the
interpretation.>>>>>>


David Peters
St. Louis