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Re: Yet more on pterosaur quad arm posture

Gregory S. Paul <GSP1954@aol.com> wrote:

> By the way, as noted by Wellnhofer pterosaurs could not elevate the humerus
> vertically as is normal in modern flying birds. It is very likely that most
> if not all pterosaurs had good climbing flight abilities. So the inability
> of basal dinosaurian fliers like Archaeopteryx and Microraptor to fully
> elevate th humerus does not necessarily refute their ability to be good 
> powered
> fliers. Contemplate it.

It is certainly worth "contemplating" the possibility that
_Archaeopteryx_, _Microraptor_ and others were capable of powered
flight despite minimal (if any) humeral elevation.  Jason Brougham
(for one) brought this up on the DML, which prompted me to take the
idea seriously.

Thus, theropods might indeed have been "good powered fliers"
(presumably by employing a deltoideus-driven upstroke).  But just
because pterosaurs are inferred to have done this doesn't
automatically mean that theropods did this as well.  How *exactly* did
theropods do it?

BTW, if these winged theropods were capable of a ground-level
take-off, then it removes the need to put these theropods in trees, in
order to provide an elevated launch.  It is sheer fantasy to suggest
that Archaeopteryx_, _Microraptor_, etc were specialized arborealists.
 So if these theropods were powered fliers capable of launching from
the ground, they would have no need to climb trees to achieve
elevation.  This is consistent with the anatomy of these winged
theropods, which is consistent with a terrestrial lifestyle.