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

evelyn sobielski <koreke77@yahoo.de> wrote:

> And of course, Neornithes = crown birds is perhaps the only higher-level 
> definition in this whole mess that is stable and widely accepted; even those 
> who synonymize it with Aves do not argue about its
> content. On the contrary, a major argument for Aves = Neornithes seems to be 
> the robustness of this clade.

Actually, the vaunted "stability" of Neornithes came about more by
accident than design.  It has a checkered history, just like
Ornithurae and Aves.

Neornithes was originally proposed (by Gadow, 1892) as a substitute
for Ornithurae.  Because Gadow included _Ichthyornis_ and
_Hesperornis_ in his Neornithes, and because these two were thought to
belong inside the crown clade, Neornithes came to be applied to the
crown clade.  Although _Ichthyornis_ and _Hesperornis_ were later
removed from the crown clade, the name Neornithes remained attached to
the crown clade, and it's pretty much been stuck there ever since.

I like Gauthier and deQueiroz's (2001) proposal that Neornithes become
a more inclusive clade than the crown, such as a node-based clade that
contains _Hesperornis_ and modern birds.