Re: Yet more on pterosaur quad arm posture

[Tim Williams <tijawi@gmail.com>]

Scott asked that I forward this to the list...

> On Thu, Jul 18, 2013 at 2:32 AM, Scott Selberg <ssselberg@hotmail.com> wrote:
>>
>> Dear Tim,
>>   I've been trying to get this up, but it's not working for me. I'm sending
>> it to you because, frankly, to me you're the person who would be most likely
>> to dismiss it (that's a good thing). Thanks.
>>
>> Where I live, about 90% of the time one startles a grey squirrel, rather
>> than climbing up into the branches of a tree it climbs a ways up the trunk
>> and then waits for the intruder to leave. Perhaps early, sickle clawed
>> maniraptors were primarily adapted to clinging to tree trunks, to escape
>> danger and to scout for prey, after which they glided or fluttered to the
>> ground or to another tree trunk. Which isn't to say that they never roosted
>> on large branches.
>>
>> It may also be that the reversed hallux did not originate primarily for
>> perching per se. It may have evolved to enable some species to land more
>> efficiently on small branches rather than dropping to the ground or landing
>> on tree trunks or large branches . I realize that the ability to perch on a
>> thin branch also results from this adaptation, but the ability to land  on
>> the branch may have been the driver since that meant that the animal needn't
>> climb out onto the branch, which we all agree maniraptors were poorly
>> equipped to do. Along these lines, this trait seems to have first evolved in
>> animals which may have fed in the trees.
>> Scott Selberg
>>