Re: Phylogeny of Maniraptora

["Tim Williams" <twilliams_alpha@hotmail.com>]

James R. Cunningham <jrccea@bellsouth.net> wrote:

> You're interpreting me correctly.  There are times when being coplanar 
> would be an advantage.  There are other times when being actively 
> non-coplanar might offer even more advantage.  I gather from your
> phrasing below that you accept hindlimb involvement in all wings associated 
> with patagiums. If so, is that a functional requirement?

I was referring to the membrane (patagium) stretched between the forelimbs 
and hindlimbs of gliding mammals - colugos, "flying" squirrels, "flying" 
possums, and the like.  The patagium links the forelimbs and hindlimbs in 
functional allegiance during gliding.  _M. gui_ probably displayed a similar 
link.


Graydon <oak@uniserve.com> wrote:

> You get something like flapping from the predatory stroke if you push a 
> basal maniraptoran out of a tree; it may not do any good, but that's what 
> its arms _do_ when trying to move rapidly, they're not the peculiar
> wide-range-of-motion things people have got.

Sorry, I don't follow.  Why would the maniraptoran flail its arms around in 
a predatory-stroke-like motion when falling from a tree?

Come to think of it, who pushed it out of the tree in the first place?  What 
I'm getting at is, if a maniraptoran can get up a tree, it must have the 
ability to get down.  Therefore, it may have evolved an apparatus that 
facilitated this route.

> If it's a maniraptoran, it can flap.  (maybe not *well*, but it can flap.)

But, *why* would it flap?  You've explained the *how*, but not the *why* of 
the predatory stroke --> flight stroke pathway.




Tim

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