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Re: Microraptor hanqingi, new species from China.



On Thu, May 24, 2012 at 10:05 AM, Don Ohmes <d_ohmes@yahoo.com> wrote:
> On 5/24/2012 9:46 AM, evelyn sobielski wrote:
>
> It has been mentioned onlist many times that the basal theropod body-plan
> was not well-suited to active foraging in trees or exploitation of the
> terminal branch environment, even with modification of distal limb elements.
>
> Once minimal powered flight was achieved, however, modification of the foot
> to facilitate flap-flying ('or flap-jumping') from branch-to-branch seems
> straight-forward, from the selective perspective.
>
> In other words -- assuming minimal vertical climbing ability, modification
> of the pes away from the cursorial condition ("loss of cursorial
> adaptations") might have occurred _after_ powered flight was achieved, not
> _as_ it was achieved -- and logically a fully arboreal theropod life-style
> awaited the development of powered flight, even if flight evolved in the
> strict tree's-down mode.
>
> I grant it seems a little messy, but even if it can be shown that the
> perching foot evolved well after powered flight was achieved, the strict
> 'tree-down' flight-evolution scenario is not excluded -- sleeping in a tree
> after a day (or night, in the nocturnal case) of ground-foraging is an
> entirely reasonable life-style, and lots of critters do it...

I think that's eminently reasonable Don - the question now is when did
the transition start to happen, and on that I think there will still
be a bit of disagreement, but perhaps it would make for a more
fruitful discussion.

-- 
Scott Hartman
Scientific Advisor/Technical Illustrator
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