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Re: Birds of Russia and Mongolia



Thomas Holtz wrote-

> In his abstract for a talk at the VII International Symposium on Mesozoic
> Terrestrial Ecosystems, Kurochkin considers feathers to have evolved
> independantly three or more times; that the digits of _Archaeopteryx_ are
> I-III, while those of ornithurines are II-IV; that Confuciusornis might be
> derived independantly of EITHER the Archie-Enantiornithes clade or the
> ornithurines; and that _Sinosauropteryx_, _Protarchaeopteryx_, and
> _Caudipteryx_ are feathered non-avian theropods (who developed feathers
> independantly of at least some "birds").

Ah yes, now I remember.  For everyone who doesn't have the abstract-

A NEW UNDERSTANDING OF EARLY AVIAN EVOLUTION

Evgeny Kurochkin 1

1 Head of Laboratory Paleoherpetology and Paleornithology - Paleontological
Institute of the Russian Academy of Sciences, 123 Profsouznaya Street,
117868 Moscow GSP-7, Russia.

During the last decades, the record of Mesozoic birds increased more than
twice. These data showed an unbelievable diversity and Worldwide
distribution of birds in the Mesozoic. At the same time, these new findings
complicated our understanding of early avian evolution, and a number of such
new Mesozoic discoveries have been differently interpreted by different
experts. The Enantiornithes, Archaeopteryx, Confuciusornis, Alvarezsauridae,
Protoavis, the feathered Chinese dinosaurs, and even Ambiortus occupy very
different positions in the available avian phylogentic hypothesis . The
Enantiornithes were a very diverse Cretaceous group of flying creatures. The
detailed morphofunctional analysis shows that they developed wing, pectoral,
and hind limb structures in parallel to ornithurine birds. A number of
synapomorphies show close relationships of the Enantiornithes and
Archaeornithes, that unites them into the taxon Sauriurae. The relationships
of Confuciusornis is problematic. Perhaps Confuciusornis presents a separate
lineage of early birds. Alvarezsauridae do not belong to Aves. Protoavis is
not a bird, but it had many features which are convergent to ones of the
Ornithurae. Sinosauropteryx, Protarchaeopteryx and Caudipteryx are feathers
theropods, which confirm that feathers originated in evolution more than
once. Ambiortus is a paleognathous neornithine, but not an
ichthyornithiform. Ambiortus and the Early Cretaceous Chinese Otogornis
belong to the order Ambiortiformes. Firm evidence supports that three wing
digits of Archaeopteryx and ornithurine birds are not homologous, and the
same is true feathers of Archaeopteryx and recent birds. All these data
force to think that some separate lineages of the feathered creatures
evolved during the Mesozoic and they had independent origin.

I have yet to see any valid sauriurine synapomorphies and would like to see
the "firm evidence" that supports non-homologous digits and feathers in
Archaeopteryx and neornithines.  Especially when everything I've heard
indicates the feathers of Archaeopteryx are completely modern.  I suppose
saying Caudipteryx et al. developed feathers in parallel to ornithurines is
better than saying they are birds though.  I do agree that alvarezsaurids
and Protoavis are non-avian.

Mickey Mortimer