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Re: Could 'four-winged' dinosaurs fly? - latest Nature
At 02:42 PM 11/16/2005 -0600, Tim Williams wrote:
Xing Xu, Zhonghe Zhou, Xiaolin Wang, Xuewen Kuang, Fucheng Zhang and
Xiangke Du (2005). Origin of flight: Could 'four-winged' dinosaurs fly?
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