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Re: Disney's Dinosaur Trailer



Pat or Jim said:
> Bats have much less massive wing muscles (relatively) than birds, and I
> admit to assuming that pterosaurs did as well.  If pterosaurs had massive
> wing muscles (again, not "flight" muscles) I'd be interested in knowing what
> they were used for.> 

probably walking quadrepedally?

The bat* walks with it's 'inner wrist' (about where the base of the
fleshy part of a human hand meets our wrist, towards the base of the
thumb) as the contact that touches the ground during it's quadrapedal
walk. I suspect the 'wrist' is probably kept at tension (in one
position) throughout a stride length.  This may be simply that there is
very little muscle to move the wrist OUT of this position during a
stride length... but since wrists function as a joint of rotation for
all points PAST it towards the ends of the fingers, well, if you press a
rotating joint to the ground it can't bend.
 
Pterosaurs left full manus impressions of their 'hands'.  This means
that the wrist is above the point of contact with the ground and this
probably preserved flexibility of the wrist.  I'm not saying that
pterosaurs had to flex their wrists during a stride length but they
could.  Since the movement is possible, perhaps these inner wing muscles
controlled wrist flexion during a walk?

-Betty Cunningham

*some bats may walk on the pad that would be equivalent to the webbing
between the thumb and forefinger of a human hand (towards the thumb more
than towards the finger)

Pat and Jim said:
> Bats have much less massive wing muscles (relatively) than birds, and I
> admit to assuming that pterosaurs did as well.  If pterosaurs had massive
> wing muscles (again, not "flight" muscles) I'd be interested in knowing what
> they were used for.
> 
> > We are talking about the inner wing here, inboard of the wrist<
> 
> I was talking about wing muscles.
> 
> >not the outer wing which was mostly (but not entirely) tendon and
> membrane.<

-- 
Flying Goat Graphics
http://www.flyinggoat.com
(Society of Vertebrate Paleontology member)
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