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Re: Perching, climbing, roosting was Re: 11th specimen of Archaeopteryx



On 11/9/2011 12:55 AM, David Marjanovic wrote:

I am agnostic on sickle-claws, at least as related to trees. Cutting
of branches while sitting on them isn't gonna happen, though.

How do you know?

The claim that a keratinous claw will slice knife-wise through wood is extraordinary, not to mention ludicrous. You should do a small study...

Left-hand up, right foot up, right hand up, left foot up, repeat...

Doesn't remind me of any theropod.

What does that mean?

Claw-ed trunk-climbers and hand-ed primates are apples and oranges.

There are plenty of claw-climbers without opposable digits around today.
They're all mammals and squamates. Compare them to Archie and weep.

No extant Archie's? That's sad, they must be extinct.

> -- So far, I don't see a reason to assume any climbing or roosting
> in any dinosaur that wasn't able to fly into a tree.

Ah! So you are strictly a "ground-upper", then? Tell me how you
manage that, in the face of a limited wing-stroke?

Did you react last time I posted this
http://www.dinosauria.com/jdp/archie/feather.htm ?

Yes, I did.

Again -- limited wing-stroke (which you imply is "anatomical fact", and state is not debatable by the masses) really takes the steam out of it -- but I would not say it is impossible. I never noticed that fighting birds make use of full wingstroke amplitude, though. Even though they have it in abundance.

> *Confuciusornis* may be an exception, but it had moderately
> grasping feet, huge curved claws on the 1st and 3rd fingers, an
> enormous deltopectoral crest on each robust humerus, and IIRC
> shorter legs than Archie, especially shorter lower legs; it was
> clearly better at trunk-climbing than Archie, even if not much.

Interesting.

Interesting? Interesting is the fact that you didn't know that. Have you
never seen a photo of *Confuciusornis*? The features I mentioned are
glaringly obvious, they're not tiny details that might not show on a
coarse-grained image. Even the monographic description, Chiappe et al.
(1999), can be downloaded for free because it was published in the AMNH
Bulletin.

You have a responsibility to educate yourself on what you're talking about.

You made the point that Confuciusornis was even better at climbing than Archie. Apparently, the point was presented as a refutation of roosting behavior in both. I repeat -- "interesting".

> -- Why climb into a tree for safety rather than hide under a
> shrub?

Because it is safer...

...right after I explained that it's not safer as far as I can see. What
have I overlooked?

You announced that 'hiding under shrubs' is as secure as tree-roosting for a small clawed-and-winged animal w/ a long feathered tail -- you also announced that sickle-claws might serve as pruning shears -- and unsurprisingly presented no supporting evidence.

Both claims fly in the face of common knowledge about the materials and physics involved.

Do you have no responsibility to educate yourself on what you're talking about?