Re: Could 'four-winged' dinosaurs fly? - latest Nature

[Jon Barber <augray@sympatico.ca>]

At 02:42 PM 11/16/2005 -0600, Tim Williams wrote:

[snip]

> Xing Xu, Zhonghe Zhou, Xiaolin Wang, Xuewen Kuang, Fucheng Zhang and 
> Xiangke Du (2005).  Origin of flight: Could 'four-winged' dinosaurs fly? 
> (Reply)
> Nature 438: E3-E4.
>
> First paragraph: We agree that a strict biomechanical analysis is needed 
> to reconstruct _Microraptor_'s locomotory mode, but we disagree with 
> several of Padian and Dial's arguments1. In addition to the six 
> _Microraptor_ specimens we described2, other similarly preserved 
> specimens3 have been discovered that also had long, asymmetrical 
> pennaceous feathers attached to the hindlimbs2. These feathers show 
> features that are functionally correlated with flight4. A large, feathery 
> surface on the legs would increase, rather than decrease1, drag during 
> running, as evidenced by the reduced or lost filamentous integumentary 
> structures on the lower legs of cursorial birds and mammals.

The reply contains this tantalizing sentence:

     _Microraptor_, which provides negative evidence for the
     cursorial hypothesis, could have taken to the air according
     to our recent biochemical analysis.

*Biochemical* analysis??? Schweitzer et al. have demonstrated the 
usefulness of biochemical analyses, but I'm hard-pressed to imagine how 
such an analysis of a fossil will demonstrate flight or gliding ability. 
The reference given for this claim is:

     Dyke, G. J., Nudds, R. M., Rayner, J. M., Norell, M. & Xu, X.
     Proc. R. Soc. Lond. B (submitted).

Of course, my lack of imagination is hardly an argument against something, 
and I'll certainly keep an eye out for that paper, but does anyone have an 
idea of what Xu et al. are talking about? Or is this one of those WFTP 
situations?

[snip]