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

Re: Greg Paul is right (again); or "Archie's not a birdy"

> Yet another reason why the definition of "Aves" should not rest on
> _Archaeopteryx_.


On Wed, Jul 27, 2011 at 12:34 PM, Mike Keesey <keesey@gmail.com> wrote:
> On Wed, Jul 27, 2011 at 10:20 AM, Thomas R. Holtz, Jr. <tholtz@umd.edu> wrote:
>> An Archaeopteryx-like theropod from China and the origin of Avialae
>> Xing Xu,         Hailu You,      Kai Du  & Fenglu Han
>> Nature 475, 465–470 (28 July 2011) doi:10.1038/nature10288
>> Received 16 November 2010 Accepted 10 June 2011 Published online 27 July 2011
>> Archaeopteryx is widely accepted as being the most basal bird, and
>> accordingly it is regarded as central to understanding avialan origins;
>> however, recent discoveries of derived maniraptorans have weakened the
>> avialan status of Archaeopteryx. Here we report a new Archaeopteryx-like
>> theropod from China. This find further demonstrates that many features
>> formerly regarded as being diagnostic of Avialae, including long and
>> robust forelimbs, actually characterize the more inclusive group Paraves
>> (composed of the avialans and the deinonychosaurs). Notably, adding the
>> new taxon into a comprehensive phylogenetic analysis shifts Archaeopteryx
>> to the Deinonychosauria. Despite only tentative statistical support, this
>> result challenges the centrality of Archaeopteryx in the transition to
>> birds. If this new phylogenetic hypothesis can be confirmed by further
>> investigation, current assumptions regarding the avialan ancestral
>> condition will need to be re-evaluated.
> Very cool!
> Yet another reason why the definition of "Aves" should not rest on
> _Archaeopteryx_.
> --
> T. Michael Keesey
> http://tmkeesey.net/

Scott Hartman
Scientific Advisor/Technical Illustrator
(307) 921-9750
website: www.skeletaldrawing.com
blog: http://skeletaldrawing.blogspot.com/