[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Gregory S. Paul on Confuciusornis
The mass does not change the feather strength itself, but alters the strength
relative to body weight, which is the key variable in question.
Sent from my iPhone
On Oct 14, 2010, at 3:46 PM, Mark Pauline <firstname.lastname@example.org> wrote:
> In the new Science out this afternoon:
> Comment on âNarrow Primary Feather
> Rachises in Confuciusornis and
> Archaeopteryx Suggest Poor
> Flight Abilityâ
> DOI: 10.1126/science.1192963
> Science 330, 320-b (2010);
> I had two questions about Paul's text.
> 1) "Nudds and Dyke (Reports, 14 May 2010, p. 887) reported that the primary
> features of the early birds Archaeopteryx and Confuciusornis were too weak to
> power flight"
> What are these "primary features" that Paul describes? How do these features
> confer weakness on the animals in question?
> 2) "the shallow-bodied basal bird was intermediate in mass to the
> Munich Archaeopteryx and the deep-bodied pigeon, so the feathers were a
> of times stronger than calculated by Nudds and Dyke (Fig. 1, A to C)."
> How does changing the mass make the feathers stronger or weaker? Isn't
> an inherent quality that depends on the structure of the feather?