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Re: Secondarily Flightless Question

At 06:44 PM 10/09/02 -0700, Jaime A. Headden wrote:
  Phorusrhacoids group together on the basis of cranial and pelvic
features. Increase in size is convergent among to lineages, with one
primitive, seriama-like lineage still capable of flight, and behaviorally
in this context may have been similar. Only tinamous today among ratites
fly, but comparison to the fossil record shows that primitively, ratites
lost flight perhaps several times. That arm and sternal features vary
among ratites makes it more difficult to assess any particular trend in
flight loss about them, but maybe _among_ them.

And it might be worth pointing out that there are flying and flightless birds living today that are actually closely-related species (or even subspecies, depending on whom you read) within the same genus. Examples are the steamer ducks (Tachyeres), Aldabra and White-throated Rails (Dryolimnas cuvieri complex), and Brown, Auckland and Campbell Teals (Anas chrysotis complex).

Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2 mailto:ornstn@rogers.com