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Re: 11th specimen of Archaeopteryx



Yes, that is the presentation I alluded to. Thanks for posting the abstract!  
The modern birds with secondaries filling the inboard wing typically have short 
humeri. Archaeopteryx also does not seem to have angled secondaries.  Scott 
Hartman would be the better individual to reply to that particular query, 
though.

Cheers,

--Mike H.


Sent from my iPhone

On Oct 27, 2011, at 5:52 PM, "Jason Brougham" <jaseb@amnh.org> wrote:

> Dr. Habib, is this the presentation at SVP Bristol that you mentioned?
> 
> Also, the literature says that some modern birds do not have humeral remiges, 
> using proximally directed secondaries to fill that role. Is it possible it 
> was the same for Archaeopteryx?
> 
> Poster Session II, (Thursday)
> FLIGHT MORPHOLOGY AND LAUNCH DYNAMICS OF BASAL BIRDS, AND
> THE POTENTIAL FOR COMPETITION WITH PTEROSAURS
> WEISHAMPEL, David, Johns Hopkins University, Baltimore, MD, USA; HABIB, 
> Michael,
> Johns Hopkins University, Baltimore, MD, USA
> Birds inherited a bipedal gait and feathered airfoils from their theropod 
> ancestry. These
> features produce specific tradeoffs with regards to launch, maximum size, 
> lift coefficient,
> and limb disparity. There are subtle effects related to the use of feathered 
> wings, such as
> the ability to utilize separated wingtip slots and extensive span reduction, 
> which have
> also influenced avian flight evolution. Combining information from structural 
> mechanics,
> aerodynamics, and phylogeny, we conclude that the basal state for avian 
> takeoff was a
> leaping launch, not a running launch. We find that several morphological 
> features of early
> birds, inherited from theropod ancestry, predisposed them to radiation in 
> inland habitats. We
> find that Archaeopteryx could sustain substantial loads on both its forelimbs 
> and hindlimbs,
> but structural ratios between the forelimb and hindlimb of Archaeopteryx are 
> indicative
> of limited volancy. Limb strength in Confuciusornis was modest, suggesting an 
> emphasis
> on cruising flight and limited launch power. We find little evidence to 
> support extensive
> competition between birds and pterosaurs in the Mesozoic. Prior literature 
> has suggested
> that pterosaurs competed with early birds for resources and may have helped 
> shape the early
> evolution of birds. There is some evidence of partitioning between pterosaurs 
> and birds in
> ecological space. Evidence from the Jehol fauna suggests that pterosaurs 
> dominated near
> coastlines during the Early Cretaceous, while birds were more important 
> inland. However,
> flight is a complex character. Flight mechanics vary considerably across 
> volant animals.
> Some flyers experience only limited competition for resources with other 
> flying species,
> and might compete most intensely with non-flying taxa. As a baseline for 
> understanding the
> interactions between Cretaceous birds and pterosaurs, the flight dynamics of 
> the two groups
> need to be compared in a quantifiable framework. Birds and pterosaurs 
> inherited different
> morphologies, and this impacted their flight regimes. Comparing the two 
> systems provides
> a basis for hypotheses related to competition in the Cretaceous, and the 
> influences on early
> avian evolution.
> 
> On Oct 27, 2011, at 4:21 PM, Habib, Michael wrote:
> 
>> Also, the possible (likely) lack of a complete inner wing and the relatively 
>> weak forelimbs (see Weishampel and Habib presentation at SVP Bristol for the 
>> latter; full paper still pending as we are adding to it).
>> 
>> Cheers,
>> 
>> --Mike H.
>> 
>> Sent from my iPhone
>> 
>> On Oct 27, 2011, at 3:55 PM, "David Černý" <david.cerny1@gmail.com> wrote:
>> 
>>> David Marjanović <david.marjanovic@gmx.at> wrote:
>>> 
>>>> What are these, other than the apparent inability to lift the wing above
>>>> horizontal?
>>> 
>>> The (admittedly controversial) feather study of Nudds & Dyke (2010), 
>>> perhaps?
>>> 
>>> Nudds RL, Dyke GJ 2010 Narrow primary feather rachises in
>>> _Confuciusornis_ and _Archaeopteryx_ suggest poor flight ability.
>>> Science 328(5988): 887-9
>>> 
>>> -- 
>>> David Černý
> 
> Jason Brougham
> Senior Principal Preparator
> American Museum of Natural History
> jaseb@amnh.org
> (212) 496 3544
> 
>