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



A follow up:

An interesting aspect of this study is that by moving pointy-snouted
Archaeopteryx (and Anchiornis, and Xiaotingia) over with pointy-snouted
deinonychosaurs, the morphological sequence of nodes up to the base of
Avialae and into birds is much more blunt-snouted. Following Zanno &
Makovicky's recent ecomorphological work, it suggests that basal birds may
have been primarily non-carnivorous (that is, omnivorous or something in
that spectrum), like oviraptorosaurs and such.

On Wed, July 27, 2011 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.
>
[snip]

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