re: Boreopterus snout holes

[Christopher Collinson <thats_mr_annoying_to_you@yahoo.com>]

--- david peters <davidrpeters@earthlink.net> wrote:


> Using Photoshop, from half a world away, and without
> an airplane ticket or hotel bill, I was able to
> provide a smidge more detail. Thank you, Mike
> Hanson, for confirming that you also saw the holes
> in the snout. That validates the use of photography
> and the computer to establish details.


No it doesn't! That Mike can see the holes doesn't say
 anything with regards to the photoshop technique. I
can see the holes just fine with out the aid of
photoshop, and that certainly doesn't validate your
interpretation of them as external nari. 

> Now, remember: _how_ we interpret those holes, and
> everything else about the skull, has nothing to do
> with Photoshop. 

At least that is what you would like to think, but
because of what you write just two paragraphs later
that's really not the case.

> At this point we can look at the ceiling and wonder
> what those holes are. Then we can look at other taxa
> to see if such holes are 'absent' or 'present'. 
>
> If I can find similar holes bounded by the nasal (in
> pink) and the jugal (in blue) in other taxa
> preceding this one and trace the character back to
> its origins, then I have a case. Conveniently, you
> can follow the evidence at various places within
> www.pterosaurinfo.com. It's all in there.


See? Your interpretation of these holes as nari, are
dependent on your observation that the jugal and nasal
are extended well anterior of the naof. This is based
on a photoshop observation and contrary to the
observations made by all other pterosaur workers. And
thus I hope you can see that it has everything to do
with photoshop. 


> On the other hand, if _anyone_ can find a pristine
> rostrum without similar holes bounded by the nasal
> and jugal _anywhere_ within the ornithocheiridae,
> cycnorhamphidae or any taxa following Scaphognathus,
> then you will have made your case. Of course, there
> could be identical bone rot in every specimen from
> every strata... but, that would be your evidence to
> present. You're also going to have to show that the
> nasal and jugal do not continue beyond the
> antorbital fenestra.


Fossils being what they are and all, I would predict
that it would be an extremely rare fossil indeed to be
so pristine with out any crack or flaked out fragments
of bone with which you could interpret as sutures and
nari. And I'm sorry, but you still have to first show
that the nasal and jugal DO continue beyond the naof.
Connecting the dots and lines on a photograph of a
pancaked fossil do not constitute appropriate lines of
evidence. 


> PS. And thank you, Jaime, for seconding the
> hypothesis of a separate naris in the Pterodactylus
> sp. AMNH 1942.


Did you  read what he had to say? That was not his
conclusion at all.

"Thus I would conclude nothing extraordinary is
present in this skull, but that Dave is right in that
the anterior portion of the aperture represents the
external naris, but not likely to represent a
complete, intact, and separate external naris."

Cheers,
Christopher Collinson



                
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