[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: More on Argentavis



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

_________________________________________________________________
http://im.live.com/messenger/im/home/?source=hmtextlinkjuly07