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Re: RECENT AVIAN PHYLOGENIES
At 03:35 PM 2/25/99 PST, Matt Troutman wrote:
><<The advantage Chiappe puts forward for his own tree, with a clade
>Pygostylia uniting enantiornithines and modern birds, is that it only
>requires a single evolution of advanced flight characteristics including
>a keeled sternum, alula, pygostyle, and strut-like coracoids. Accepting
>Saururae as a taxon would require that these characters arose twice,
>once in the enantiornithine line and once in modern birds. Chiappe, in
>short, concludes that "Saururae" is clearly paraphyletic.>>
>Pygostylia is actually Chatterjee's arrangement of birds above
>_Protoavis_. Looks like Chiappe abandoned 'Ornithothoraces'.
No, I believe it was still in there. I think Orenstein miswrote a bit of
the above: Pygostylia was (if memory serves) Confusciuornithidae +
Ornithothoraces, and Ornithothoraces was enantiornithines plus orniturines.
(Chiappe mentione briefly a second taxon related to _Confuciusornis_, and
these two together formed the confuciusornithids).
Thomas R. Holtz, Jr.
Vertebrate Paleontologist Webpage: http://www.geol.umd.edu
Dept. of Geology Email:email@example.com
University of Maryland Phone:301-405-4084
College Park, MD 20742 Fax: 301-314-9661