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Re: Science feather strength debate
Erik Boehm <firstname.lastname@example.org> wrote:
> Sort of like hugging the tree tight to get a grip? Do we have any other
> example of something like that? seems to me that squirrels can sufficiently
> grip trees, without
> prehensile hands, or a keel.
Yeah... but squirrels are quadrupedal mammals with mobile wrist and
Basal birds, like non-avian theropods, were not built for climbing.
Cursorial bipeds with wrists and ankles only capable of movement in a
single plane; long inflexible fingers; no specialized perching foot...
If confuciusornithids did climb, then they would have had to clamber
up trees using all fours. (No, I don't buy the WAIR hypothesis -
especially if confuciusornithids could'nt elevate the humerus above
the dorsum.) If the forelimbs played a major role in pulling them up
trunks, then extra pectoral musculature could have helped. I'm not
saying that this is why _Confuciusornis_ had a keel. But I would
hesitate to assume it was associated with execution of a flight
stroke. It could have; but any such flight stroke would be
> From what I gather, the manus doesn't exactly look adapted for getting a good
> grip either, does it?
No, dead right. And nor does the foot. But at least the hallux is
lower down on the foot compared to the primitive theropod condition.
> It seems to me, that it has more than enough adaptations to allow it to ridge
> soar in conditions presently found in many places.
_Confuciusornis_ would have to wait for a breeze of the right
magnitude and direction in order to pull off this "soar". Until that
happens, the poor bird is stuck on the ground whistling Dixie... ;-)