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Re: Defending Photoshop, defending the interpreter



David Peters (davidrpeters@earthlink.net) wrote:

<You've never heard of, oh, what is the term for ichnites that appear a layer
or two down from the original skin impression layer? Even more pertinent is the
point that a fossil is more than just bones in the case of Solnhofen fossils.
The soft tissues of the creature are still there, only substantially erased or
enlarged via calcification. Yet bedding planes follow the body contours to such
an extent that sometimes the bones have to dug out.>

  What you are trying to recall are "underprints" which, I might remind anyone,
bear very little relation but digit orientation to the original surface print.
That is, the morphology of the print is obliterated in layers below due to the
effect of depressing great weight through underlying layers. This occurs ONLY
in soft layering such as mud and wet sand, and not through particulate
deposition such as limestone, chalk, ash, etc., as the pressures and the
inclusion are too small to create underprints.

  Then there are "overprints", which are infillings of the original fossil or
dried print, and they conform to the inner shape in general, but as above, they
loose all definition of details, and become irregularly shaped blobs of toes.
Some fossils will even pick up a layer of overburden above them due to the
compressing pressure above moving around the inclusion. This occurs only in the
fine particulate depositions, to my knowledge, such as siltstones and
limestones, but not chalks. Even then, the massive amount of pressures many
fossils in various chalks can accure will destroy the bone to some spectacular
degree, but the particulate deposition conforms _around_ the bone shape.

  So, until someone comes up with primary data to show that bones leave
distinct traces of themselves with joints and cartilage and everything in
layers below the bedding plane, and by this evidence not the tracings we've
seen so far, we can't argue that those tracings are that evidence.

<If only one or two specimens showed the details I propose, then yes, blame the
interpreter. But when dozens do.>

  And once again, one tends to find what one expects to find in such blotchy
fossils. Just like interpreting ink-blot tests. Or splotches on the adobe walls
that sometimes look like Mickey Mouse, or the curious "shapes" one can see on
the camel on packs of Camel's cigarettes. One should expect to find things one
can tend to find things in blotches, which is why ink-blot tests are
administered: they give results.

<And when they don't add steps to phylogenetic analyses.>

  Which are meaningless when the data put into the analysis is nonexistent. You
are testing your own expectations.

<Or when deep chord wing membranes are sought but not found.>

  And the only evidence I have ever seen for *Sordes* lacking an ankle
attachment to the cheiropatagium -- a "cruropatagium" if you will -- was a
contradiction to Unwin and Bakhurina by Dave which the authors of the
wing-design paper promptly rejected. In fact, the "evidence" against the wing
design Unwin and Bakhurina presented was more of this Photoshop "magic" by
assuming the wingform should conform to a set of preconceived notions, we never
really went out and tested it on realistic materials or taphonomic experiments.

<Or a uropatagium that stretches from one leg to the other without touching the
tail,>

  While I am sure it's possible, I would require primary data to show that this
could not happen taphonomically.

<or a propatagium with actinofibrils,>

  Or with a covering of "hairs". Or covered in tooling traces.

<or mistaking an anurognathid embryo for an ornithocheirid,>

  Or mistaking an embryo for an adult. Much less assume we should know what an
ornithocheirid embryo should look like.

<or reconstrucing a pterosaur skull upside down,>

  Or misinterpreting cracks because it's convenient to "see" a palatal complex
versus a dorsal cranial roof, or in fact a complex of dorsal, ventral, and
lateral cranial bones that have collapses. But then, none of these have been
scavenged, ever, so we should expect every fossil to be found entirely complete
except where the slab disappears. I find this probability a complete
contradiction to the tendency of fossils to be incomplete. But then, examine
non-laminated fossils. Or better yet, study fossils of terrestrial vertebrates
and other animals on slabs in other lagerstaetten, such as the Eocene Green
River, the Miocene Messel, the Oligocene Quercy deposits, etc.

<or finding a pterygoid where none was notice before,>

  Possible. Certainly some fossils are never fully described. But then, many
fossils tend to be crushed to the point that the many rod- or plank-like bones
within the skull become cracked fractured and, while a pterygoid was likely
there in life, it could very well be absent or shattered beyond recovery to
date. But it is possible to interpret some bones as pterygoids. How to prove
it, that's a question one should consider.

<or a phalanx four submerged beneath legs.>

  Or a missing long bone, or another animal's limb, or simply an artifact of
the slabs's coloration. One must discount other possibilities.

<All these observations have been fixed in Photoshop.>

  "Fixed"? Kind of the wrong word to be using right now.

<If you have any problem with any of them, it is imperative for the sake of the
science, that you start making notes and repairs to the work. Point by point.>

  Why? Why can't YOU try to find ways to test your own technique? Double blinds
and such like? I have, as have others -- and this is getting repetitive --
found various problems and improbabilities and down-right erroneous conclusions
in this "recovery" technique, which simple observation of the slabs would have
reconciled. Indeed, from cracks becoming "nostrils", to squiggly "frills" all
over the place, to pretend "bones" centimeters below the real ones on the KJ
specimens, to the very concept of "unfossilized" yet preserved "bone" for
"neonates", "teeth" on the prepared and studied rostrum of *Thalassodromeus*
made by interpreting irregularities on the bone _surface_, to Bennett's
contending resolution problems with your tracings, to fake "wing unguals" made
from color inclusions and dendrites, to broken bone being interpreted as a real
bone margin....

  At what point should what has been said already simply be abandoned for the
sake of such further information that we shoudl use YOUR method to contradict
YOUR method, yet one has never seen you describe this method in detail to back
up your _published_ commentary on findings? It makes me think this is more an
intuitive practice than a scientific one. Testing, by using light intensity
changes, lighting angle, corss-spectrum lighting, and actual surface
examination (say, using a mono-colored cast so that blotches no longer confuse
the eye so for actual SURFACE defects that might show as bones). I think only
when one has begun to do this, only then and the data supports what has been
done before, the Photoshop technique will only be an illustrator's technique.

  Cheers,

 It
> is imperative that giant pterosaur phalanges be exposed as tree trunks. That
> slow-growing 'morphing' juvenile pterosaurs are exposed as phylogenetic
> series,
> rather than ontogenetic. That mechanical pterosaurs be given the proper wing
> shape. And that extremely tiny juvenile pteros be exposed as pin scratches.
> 
> I'll give you credit, as I gave Chris Bennett credit, if you do.
> 
> 
> David Peters
> 
> 
> >
> >
> >   Cheers,
> >
> > Jaime A. Headden
> >
> > "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
> >
> > __________________________________________________
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> 
> 


Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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