Re: Dinofest

["Jonathan" <spockjr@email.msn.com>]

>Jonathan wrote:
>
>>His argument was that after death, as the skin deteriorated,
>>small ligaments forced the collagen fibers in Sino to stand erect,
>>so arguing that the fibers were underneath the skin.  Also, he
>>argued that the fibers were only present along the midline of the
>>body, and not on the sides


Toby wrote:
>Is he supposing, then, that the collagen fibrils existed only on the dorsal
>mid-line of Sinosauropteryx?

It seemed as such at the time

>>(Phil Currie's talk which preceded Geist's,
>>specifically mentioned fibers preserved on other parts of the body,
>>and that they are hollow).


>Is Currie supposing patches of feathers all over the body?  Couldn't have
>been many of them.

He is and sure there could've.  Most of them simply rotted away with
the rest of the flesh.


>In fact, this argument appears to be about the biophysical properties of
>protein fibers in general.  I'd bet (i.e. speculate) that the properties in
>question are not very sensitive even to the chemistry.  Take any protein
>fiber, stretch it, dry it, and randomly shear it.  Does it tend to adopt
>erect structures with a tendency toward hollow cylinders?  I don't know,
but
>the answer could well be that it does.

That is true, anything is possible, some things are just less likely
than others.

>>And isn't Geist a respiratory physiologist???
>>Anyway, 3 cents worth.

>Geist is from Ruben's lab.  What they try to do there is to ask
>physiological questions.  Paleontology has recently, and for excellent
>reasons, moved in the direction of the quantitative comparison of multiple
>morphological features, i.e. cladistical analysis.  What Ruben and a few
>others do is to ask, "OK, but what did these characteristics mean for the
>physiology of the paleocritter?"  Important questions, but very difficult
to
>answer.  In any case, I don't think Geist was arguing that Sino was a sea
>snake.  He's arguing that we can't assume that every spikey thing is a
>feather, or is even necessarily keratin.  Currie's observation that the
>structures are also found off the dorsal mid-line and have a tendency to
>hollowness is not really inconsistent.  Perhaps the structures are
feathers,
>after all.  Its just that we're a long way from having convincing evidence
>of anything.
>
>  --Toby White

The people in Geist's lab work on the physiology
of extant animals (and I'm sure they do great work) and are not trained
paleontologists (to my knowledge).  It seems to me that they know almost
next to nothing about dinosaurs, let alone interpreting fossils (at least
that's the idea I get when I read their papers on dinosaurian anatomy).
It's always healthy to have alternative hypotheses in science but what are
their credentials for making such statements in light of the work that some
of the top minds in paleontology have carefully scrutinized?
It's true, the structures on Sinosauropteryx may not be feathers but in
weighing all the evidence it's actually very convincing.  It would, in
fact, be the most parsimonious explanation at this point.

Jonathan Weinbaum

Spockjr@msn.com