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Re: flight stroke (pretty short)

David Marjanovic wrote:
> there are so many groups that
> practice diverse variants of gliding do I think 
> that it's likely to tell something if any of them 
> does or does not show a certain behavior.

I'm just pointing out that theropods are considerably
different from the various gliding groups, so it may
not be wise to depend on those for information. 
> Hm... I think this implies that gliders would just
> as quickly be outcompeted by incipient flappers.

Pterosaurs had begun to decline by the LK, correct? 
> Might still provide a selectionary advantage if it
> tumbled back far enough away :-)

Yes, I suppose it would if there were a reason to fly

> I just wonder what exactly the disadvantage of a
> long tail is. 

It may just be an indicator of how much time an animal
spends in the air. The tail of theropods is agreed to
be a counterbalance, but if your primary means of
locomotion (flight) is hindered or has no use for a
tail, it will degenerate. I'm not so sure the tail
would cause a bird to nose-up as I originally
suggested. There may be sufficient lift produced by it
to keep the body level after all. I still like the
idea of flapping evolving from quadrupedal climbers
reaching for branches. I don't see any problems with
the hypothesis. Really, how could you shoot it down?  

> Sorry, depends on how close the elbows are held at
> the body. I mean long femora that could reach the 
> shoulders to seal the entire gap.

The flight feathers would fill that gap.
Waylon Rowley 

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