[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: Confuciusornis feather length and flight mode



  I wonder if this paper was being finalized in response to that earlier paper, 
and could not incorporate the disagreement early enough, or even test the 
disagreement? I don't have the paper, so do not know if they cite the responses 
at all.

Cheers,

Jaime A. Headden
The Bite Stuff (site v2)
http://qilong.wordpress.com/

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 
Backs)





----------------------------------------
> Date: Mon, 21 Mar 2011 20:59:00 -0400
> From: jaseb@amnh.org
> To: bh480@scn.org
> CC: dinosaur@usc.edu
> Subject: Re: Confuciusornis feather length and flight mode
>
> Well, I'll be the first to say it. This paper does not seem to have
> incorporated the data from Zheng et al. that Nudds et al. acknowledged in
> their response last year (Science, Vol 33), page 320-d, 15 October 2010.
> DOI: 10.1126/science.1193474). At that time Nudds et al. wrote that some
> specimens (or possibly a distinct, volant, species) of Confuciusornis may
> have been capable of flapping flight.
>
> Though the primary feather length of Confuciusornithids is shown in this
> new paper to group with volant ornithurines, the authors disregard the
> possibility of flapping flight again. This conclusion seems to be based on
> the conclusions of their earlier paper (and several other papers). This is
> puzzling considering their admission that flapping flight was possible, so
> long as Zheng et al's rachis measurements were used.
>
> Perhaps they had a chance to examine Zheng et al.'s specimens and
> ultimately disagreed about the rachis diameters?
>
>
>
> > From: Ben Creisler
> > bh480@scn.org
> >
> > A new paper about Confuciusornis:
> >
> > WANG X., R. L. NUDDS, G. J. DYKE (2011)
> > The primary feather lengths of early birds with respect to avian wing
> > shape
> > evolution.
> > Journal of Evolutionary Biology advance online publication
> > Article first published online: 18 MAR 2011
> > DOI: 10.1111/j.1420-9101.2011.02253.x
> >
> >
> > Abstract
> > We examine the relationships between primary feather length (fprim) and
> > total arm length (ta) (sum of humerus, ulna and manus lengths) in Mesozoic
> > fossil birds to address one aspect of avian wing shape evolution. Analyses
> > show that there are significant differences in the composition of the wing
> > between the known lineages of basal birds and that mean fprim (relative to
> > ta length) is significantly shorter in Archaeopteryx and enantiornithines
> > than it is in Confuciusornithidae and in living birds. Based on outgroup
> > comparisons with nonavian theropods that preserve forelimb primary
> > feathers, we show that the possession of a relatively shorter fprim
> > (relative to ta length) must be the primitive condition for Aves. There is
> > also a clear phylogenetic trend in relative primary feather length
> > throughout bird evolution: our analyses demonstrate that the fprim/ta
> > ratio
> > increases among successive lineages of Mesozoic birds towards the crown of
> > the tree (‘modern birds’; Neornithes). Variance in this ratio also
> > coincides with the enormous evolutionary radiation at the base of
> > Neornithes. Because the fprim/ta ratio is linked to flight mode and
> > performance in living birds, further comparisons of wing proportions among
> > Mesozoic avians will prove informative and certainly imply that the aerial
> > locomotion of the Early Cretaceous Confuciusornis was very different to
> > other extinct and living birds.
> >
> >
> > --------------------------------------------------------------------
> > mail2web.com - Microsoft® Exchange solutions from a leading provider -
> > http://link.mail2web.com/Business/Exchange
> >
> >
> >
>
>
> Jason Brougham
> Senior Principal Preparator
> Department of Exhibition
> American Museum of Natural History
> 81st Street at Central Park West
> 212 496 3544
> jaseb@amnh.org
>