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Re: Boreopterus snout holes

----- Original Message -----
From: "Christopher Collinson" <thats_mr_annoying_to_you@yahoo.com>
Sent: Friday, August 05, 2005 8:52 PM

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.

I, too, can see them. I can also see that the skull has first been _squished flat_ by the weight of the overlying Lower and Upper Cretaceous sediments and probably much more, and then been _split_ -- not exactly through the middle like the wing phalanges we saw yesterday, but still on occasions through the bone. For example, the tracing http://www.pterosaurinfo.com/boreopterus_insitu.html does not show the area where a sizable chunk of bone has broken out of the lower jaw. Just half of its left edge is indicated (as a thick, short line). I'll do a tracing of that one, too, to show all breaks I can find.

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.

I've never understood why anyone would trace "elements" on bone as well as on matrix. Skull bone sutures are emphatically not ephemeral. With the specimen at hand, they are very hard, often impossible, to overlook (if they aren't fused, I mean!), and they are about the first thing for which people _search_ when they discover a fossil skull. To believe one could do better based on a coarse-grained photo (yay, this time the pixels are "only" _half a millimeter_ across -- woo-hoo!) that probably doesn't show any sutures... perhaps I can see the jugal-maxilla suture that is shown in the tracing (the vertical one, there where the jugal ends in all other vertebrates), but that seems to be all.

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.

I doubt anyone can find a naris bordered by both the nasal and the jugal in _any_ vertebrate -- except for the antorbital fenestra of certain archosaurs (like *Monolophosaurus* and *Sinraptor*). A jugal extending forward all the way to the nasal would be _very_ bizarre.

 You're also going to have to show that the
nasal and jugal do not continue beyond the
antorbital fenestra.

On the base of that photo I can't. I'll try it anyway, but it won't be falsifiable as long as all we have is that expressionist pointillistic painting called a "photo".