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Re: Science feather strength debate



Heh, people can "refudiate" me all they want, but let's be clear what
that implies:

1) 10 specimens, most with at least faint feather impressions, several
with excellent and easily seen impressions, all with the flight
feathers ending in the same location at the elbow (i.e. no variation
in the end point that would imply randomness or missing elements)

2) An exceedingly low-energy depositional environment (i.e. no
plausible environmental mechanism for removing the tertials),
corroborated in the best preserved specimens as there's no evidence of
any displacement to the other feathers of the arm and tail.

3) In the Thermopolis specimen there is dino-fuzz preserved...which
presumably wouldn't be more durably attached than tertials.

Honestly...if the tertials are so easy to remove that it happened in
all the speccimens, even those with undisturbed tail and wing
feathers, how would they stay on during flight?

This smells like special pleading to me, and in all honesty I don't
think we'd even be having this discussion if the entire thing was
framed as "trying to understand the 'first bird'."  But that's another
issue altogether.

-Scott

On Mon, Nov 15, 2010 at 5:51 PM, Tim Williams <tijawi@gmail.com> wrote:
> Erik Boehm <erikboehm07@yahoo.com> wrote:
>
>> I'd be more inclined to believe they tertials just weren't attached as well, 
>> or something else that leads to just a preservation artifact.
>
>
> Without wanting to refudiate Scott Hartman, I concur.  But I'd be
> quite happy to be convinced that the absence is real.  Because the
> humerus of _Archaeopteryx_ is quite long compared to the birds that
> came after it, this would translate into a sizeable gap.
>
>
>> Otherwise, it seems like Microraptor would have a more bird like wing than 
>> Archie, which is odd (though this is hardly an argument
>> against the possibility).
>
>
> I know that coverts have been reported for _Microraptor_, but I wasn't
> aware that anyone had found definitive humeral feathers
> (tertials/tertiaries).
>
>
> Also, unless something has changed recently, AFAIK it is not known
> if_Confuciusornis_ had humeral feathers.  In many specimens the
> primaries and certain rectrices are clearly defined, but the degree of
> preservation is poor for most of the other feathers.
>
>
> Cheers
>
> Tim
>



-- 
Scott Hartman
Scientific Advisor/Technical Illustrator
(307) 921-9750
www.skeletaldrawing.com