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Re: Ratite phylogeny



At 08:42 PM 1/14/2004, John Bois wrote:
I propose that the
emu/cassowary clade shares a small, non-flying ancestor that subsequently
grew large, whereas the proto-ostrich was a flying bird until becoming
too large to sustain flight capacity. Fundamentally different wing growth
patterns in ostriches and emus supports both multiple flight loss events
and separate mechanisms leading to flight loss within this clade.

The idea that ostriches arose from large flying ancestors is not new; see Feduccia's books. I find ths all quite reasonble on its face; flightlessness certainly evolved repeatedly in rails, so why not in ratites?



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Ronald I. Orenstein Phone: (905) 820-7886
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