Re: New Zealand

["Matthew Troutman" <m_troutman@hotmail.com>]

>    If they flew, why do we lump them together with other ratites and =
>draw conclusions from them?

     All ratites flew at one time or another, or rather, their ancestors 
did. The popular theory that ratites were drifters on floating 
continents is falling out of favor. A new order of volant, paleognathous 
birds, the lithornithids, has been found in Paleogene deposits. Peter 
Houde has described them and has emphasized that all living ratites got 
to their present positions through flying ancestors. All of the ratites, 
though related, did not come from some common, flightless ancestor, but 
from flying ancestors. 

This has brought together a new classification of the Palaeognathae that 
puts them, in the minds of some, as relatives of Galliformes           ( 
chickens, fowl). Anybody who knows about ornithology can tell you that 
galliformes are related to anserifromes, but this has been challenged ( 
and reviewed favorably by Feduccia). Actually there is a lot of evidence 
supporting this hypothesis such as the morphology of the flight 
apparatus in galliformes and tinamous. Anseriformes may still be closely 
related to galliformes ( if Diatryma is a link between the groups as 
supported by Andors). But other evidence supports a "shorebird" 
relationship and a relationship with flamingos for anseriformes as 
suggested by Feduccia and Olson. 

But back to the kiwi. The kiwi is definitely lumped with other 
palaeoghaths because of its palate of course, inner ear morphology , 
tongue apparatus, and DNA hybridization that suggests that the kiwi's 
ancestors are related to the emu and cassowary. Houde suspects that the 
kiwi's ancestors are related to _Paracathartes_ lithornithids     ( by 
the way, lithornithids are paraphyletic according to Houde).

This is why we lump the kiwi with other ratites and draw conclusions 
from them. 

 
Houde, P. 1986. Ostrich ancestors found in the Northern Hemisphere 
suggest new hypothesis of ratite origins. Nature 324

Houde, P. 1988. _Palaeognathus birds from the early Tertiary of the 
Northern Hemisphere_. Cambridge Mass.: Nuttall Ornithological Club.

If you can't find these anywhere just look through _The Origin and 
Evolution of Birds_ for an excellent summarization by Feduccia.

 WMattTroutman






>John V Jackson    jjackson@interalpha.co.uk




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