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RE: 11th specimen of Archaeopteryx

> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Oct 27, 2011, at 3:42 AM, Tim Williams wrote:
> > Yes, there are several lines of evidence that _Archaeopteryx_ was 
> > incapable of sustained, flapping flight.  _Confuciusornis_ too; and 
> > probably _Sapeornis_ as well.  If this is true (and I'm sure not 
> > everyone agrees!) all basal birds might have been gliders.
> > Nevertheless, it is possible that these gliders might have 
> used simple 
> > flapping motions in order to gain height or added forward momentum 
> > during the glide.
> This is certainly not impossible, but it should be noted that 
> any model suggesting a "limited flapping" precursor needs to 
> consider the potential for appropriately manipulating 
> vorticity on the wing (and, in this case, rapidly increasing 
> circulation and abruptly reducing it - otherwise, the animal 
> loses more than it gains).  I have yet to see this even 
> whispered in the literature with regards to early birds, 
> which is pretty concerning.

I wonder to what degree "controlled flapping descent" may have a role here?

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA