[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Science feather strength debate
> 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.
> 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 Hartman
>> Scientific Advisor/Technical Illustrator
>> (307) 921-9750
> Jason Brougham
> Senior Principal Preparator
> American Museum of Natural History
> (212) 496 3544
Senior Principal Preparator
American Museum of Natural History
(212) 496 3544