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Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)



> > 5 ft does not seem enough of a vertical drop to
> stimulate the initial 
> > transition from a cursorial predatory biped that
> utilizes isolated trees 
> > for roosting/nest/perch-hunting to the same, only w/
> an initial 
> > parachuting/gliding capacity. Could we change that to
> 5m? :D.
> 
> Maybe not. Some say the vegetation on the islands where
> Archie apparently 
> lived was only 3 m high.

I would be happier if we didn't. Anything *above* ground-effect altitude for 
Archie (~60 cm or so) is enough.

> However, nesting in trees does not appear to be
> plesiomorphic even for 
> crown-group birds.

I have not seen anything to suggest that tree-nesting might precede perching, 
and I have seen a lot of arguments against it. *Confuciusornis* makes sense as 
a tree-nester. But Archie? Why should it, why would it and how could it?

> > Works especially well in an area where trees are
> well-scattered, and there 
> > is little undergrowth.
> 
> There may have been _only_ undergrowth.

This was my point. Any reconstruction of Archie climbing spread-limbed up some 
palm tree - FORGET THAT. There is nothing in favor of it, and a lot that speaks 
against it.

But:
http://piclib.nhm.ac.uk/piclib/webimages/0/35000/900/35981_big.jpg
Leg position roughly like this, arms different - humerus ventrally and lower 
arms/hands grasping forward, to ascend hand-over-hand a near-vertical slope. 

Possible? Was there anything that would have *prevented* it from doing it? 
(This is not a mock question; I have not looked into this. Wrong caudal 
vertebrae for me, and too many teeth ;-) )


Regards,

Eike

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