Re: More on Argentavis

[Tim Williams <twilliams_alpha@hotmail.com>]

Evelyn Sobielski wrote:

> Gastornithids are Neognathae incertae sedis; not
> higher landbirds (but more due to dating than to
> anything else), but that's all that can be agreed upon
> now I think. (Anyone know of any good post-2000 refs?)

Livezey and Zusi (2007) put gastornithids (_Diatryma_ &c) in the 
Galloanseres.  In his recent JVP paper on the Walbeck birds, Mayr (2007) 
assigned gastornithids to the "Anserimorphae".

> In any case, not quite. Flight capabilities of
> galliforms for example are not too well-developed, but
> also very rarely lost (not quite as rarely as in
> passeriforms, but far more rarely than in the usually
> well-flying Anseriformes).

True.  In all known cases of flightlessness in galliforms, this is 
correlated with living in an insular environment.  This applies to most 
examples of flightlessness in neognaths.

> Giant size on continents, yes. That's probably a
> matter of "the early bird...", catching the ground bus
> before the mammals hopped on in force.

Overall, flightless birds have done quite well co-existing with mammals.  
Until, that is, humanity came onto the scene (along with his feral 
entourage).  Many lineages of flightless birds did persist to the 
Pleistocene-Holocene, irrespective of whether they are 'big' or 'small', or 
lived on islands or continents.  It was _Homo sapiens_ who did most of these 
in.  For example, although some lineages of large flightless birds died off 
before humans clapped eyes on them (e.g., gastornithids, phorusrhacids?, 
_Eremopezus_), many other equally ancient lineages lived on (e.g., 
dromornithids, most ratite families).

Cheers

Tim

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