Re: Science feather strength debate

[Jason Brougham <jaseb@amnh.org>]

> Mr. Hartman,
> 
> I am sure that your reasoning and evidence are solid, and I can certainly 
> believe that Archaeopteryx had no tertiaries. Yet  I am curious why your 
> excellent 2007 monograph on the tenth Archeopteryx mentions faint, fuzzy, 
> impressions which "may stem from the tertiaries"? The outline drawn in figure 
> 3 also shows what may be tertiaries. That truly is a breathtaking paper, 
> congratulations on it.
> 
> I am myself always very wary about making definitive statements about plumage 
> based on negative evidence. I'm not even convinced that Scansoriopterygids 
> didn't have wings.
> 
> The reason is the type specimen of Longipteryx, IVPP V 12325. (Chinese 
> Science Bulletin vol. 46 no. 11 june 2001) It preserves body feathers and 
> fuzzy secondary coverts, but apparently no primaries or secondaries at all. 
> Certainly no large rachises are there. It has a  keeled sternum and is an 
> obvious powered flier, but the primaries and secondaries just didn't preserve.
> 
> Again, I consider it risky to make conclusive statements based on reasoning 
> like "if the tail feathers are preserved, why aren't the wing feathers? It 
> must not have had any". Fossilization is too complex and contingent to be 
> sure of such matters, and I feel like we're always one fossil away from being 
> proven wrong.
> 
> -Jason
> 
> On Nov 15, 2010, at 10:36 AM, Scott Hartman wrote:
> 
>>> I'm not wholly convinced that _Archaeopteryx_ lacked humeral feathers
>>> (= tertiaries or tertials).
>> 
>> As I presented at SVP in 2007 the tenth specimen actually demonstrates
>> that Archaeopteryx lacked tertials...specifically because it shows an
>> imprint by the humerus that clearly isn't a veined feather.  Whether
>> it represents  an inprint from the body, or could represent some sort
>> of extension of the soft "dinofuzz" material onto the arm it simply
>> isn't even close to a flight feather.  And because there is an
>> impression there, and moreover one made from a far more delicate sort
>> of soft tissue then the relatively stiff flight feathers, it's no
>> longer tenable to argue that it's some sort of trick of preservation.
>> Archaeopteryx lacked tertials.
>> 
>> -Scott
>> 
>> 
>> -- 
>> Scott Hartman
>> Scientific Advisor/Technical Illustrator
>> (307) 921-9750
>> www.skeletaldrawing.com
> 
> Jason Brougham
> Senior Principal Preparator
> American Museum of Natural History
> jaseb@amnh.org
> (212) 496 3544
> 
> 

Jason Brougham
Senior Principal Preparator
American Museum of Natural History
jaseb@amnh.org
(212) 496 3544