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Re: nostrils?



Matthew Troutman wrote:

>      It should be noted that the posteriorly displaced nostrils are not
> seen in enantiornithines. And there is little concensus on whether they
> had rhamphothecacus beaks. And also this "displacement" may be more
> apparent than real. It probably has to do with the edentalous beaks seen
> in Neornithine birds ( possibly basal in Aves?) where a large extension
> of the premaxilla was developed to accomadate a beak. This caused a
> "shift" in the position of the nares in general appearance.

I've been wondering if it developed because of the "bow wave' that a
bird or plane or other flying object develops in the front.  You
wouldn't put in-take valves in the absolute front of a plane unless you
have a processing area to handle the high impact air, right?

Whatever the face is made of, whether beak or bone or a combination
even, it seems to me that the make up won't affect the major silhoette
much.  Pterasaurs seem to share the same facial layout as modern birds
and they used bone.  Birds use a combination of bone and beak.  I think
it's an example of convergent evolution.  (we still are avoiding
bats-any species that has a member that can take it's chin, wrap it up
over it's head and look through the 'eyeholes' in it's chin is just
plain wierd)

So the nostrils may have moved as flight became more important to these
animals.  Better flying capabilities=nostrils to the aft of the leading
edge.  So maybe birds were ALL lousy flyers like Archie when they
started out.

> But it
> should be noted that Confuciusornis and Gobipteryx ( please note that I
> do _not_ endorse a close relationship between the taxon contrarily to
> Hou et al. 1996) do not show a marked shift in the position of the
> nares.

they don't show a shift based on which nostril design, dinosaurs to the
leading edge or modern birds to the aft of the beak?

-Betty Cunningham