Re: Defending Photoshop

[David Marjanovic <david.marjanovic@gmx.at>]

> 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?

> 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?

> (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?

> 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.

(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?

> 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.

> 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.

> 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.

> 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).