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



Absolutely amazing fossil. We are so lucky we lived to see it.

I guess Xu excluded crown group birds in his cladogram. The experts here 
probably know why. 

Xu comes up with several amazing results.

Some of his trees make Similcaudipteryx and Incisivosaurus into basal 
therizinosaurs. That's fascinating.

And they also make Epidendrosaurus and Epidexipteryx the most basal avialans. 
Since Xu felt that Epidexipteryx wasn't volant (since it didn't have wing 
feathers), I guess that makes it possible that the last common ancestor between 
birds and Archaeopteryx possibly didn't fly either?


On Jul 27, 2011, at 1:20 PM, Thomas R. Holtz, Jr. wrote:

> Been very hard to keep quiet about this one for oh these looooonnnnnggggg
> months:
> 
> 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.
> 
> -----
> 
> Larry Witmer's News & Views:
> http://www.nature.com/nature/journal/v475/n7357/full/475458a.html
> 
> -----
> 
> Various media reports:
> 
> http://cosmiclog.msnbc.msn.com/_news/2011/07/27/7179711-oldest-bird-knocked-off-its-perch
> 
> http://www.nature.com/news/2011/110727/full/news.2011.443.html
> 
> -----
> 
> Basic gist of story: discovery of (yet another boring generic-looking)
> feathered paravian from China that, when included in a phylogenetic
> matrix. pulls Anchiornis and Archaeopteryx together with itself to form
> Archaeopterygidae, and Archaeopterygidae pulled over as basal
> deinonychosaurs rather than avialians.
> 
> (Hence the Greg Paul comment: Greg and Ken Carpenter had argued as early
> as the mid-1980s that Archaeopteryx was a basal member of the
> Dromaeosauridae-line rather than the bird line.)
> 
> Statistical support for this position is not tremendously strong, so this
> is by no means written in stone. (Indeed I know of at least one study
> coming soon which will turn all of this inside out: however, that paper
> lacks the Xiaotingia zhengi data).
> 
> Cool stuff.
> 
> Thomas R. Holtz, Jr.
> Email: tholtz@umd.edu Phone: 301-405-4084
> Office: Centreville 1216
> Senior Lecturer, Vertebrate Paleontology
> Dept. of Geology, University of Maryland
> http://www.geol.umd.edu/~tholtz/
> Fax: 301-314-9661
> 
> Faculty Director, Science & Global Change Program, College Park Scholars
> http://www.geol.umd.edu/sgc
> Fax: 301-314-9843
> 
> Mailing Address:      Thomas R. Holtz, Jr.
>                       Department of Geology
>                       Building 237, Room 1117
>                       University of Maryland
>                       College Park, MD 20742 USA
> 

Jason Brougham
Senior Principal Preparator
American Museum of Natural History
jaseb@amnh.org
(212) 496 3544