Re: FLIGHT VERSUS BROODING

["Richard Swigart" <rswigart@worldnet.att.net>]

-----Original Message-----
From: Jonathan R. Wagner <znc14@TTACS.TTU.EDU>

this is out of context, but I would like to comment on the assumption that
increased attachment area and air-sacs are needed for sustained flight. read
below.


>>so they do not need large sterna. Increased attachment area for
>>flight muscles, and increased ventilation of air-sacs needed to sustain
>>flight, are the best explanations for the large sterna of these theropods.
>>


    Flight is not restricted to birds alone.  Bats and pterosaurs managed
flight quite well without the increased attachment area for flight muscles,
and air-sacs needed for sustained flight.
    In light of this, I would suggest that air-sacs developed for another
reason -- high altitude perhaps.  I don't think either are needed for
sustained flight, or someone needs to tell the bats to quit migrating.

Richard Swigart
rswigart@worldnet.att.net