Re: [Re: Origin of feathers]

["Jaime Headden" <jaemei@hotmail.com>]

<How is a stiffened tail helpful in an arboreal lifestyle?>

  I gave an example in my other post of how a long stiff tail is useful, 
whether with a bony core or with a quill structure, its the same.

<Wouldn't it get in the way most of the time and wouldn't it make more 
sense to have a prehensile or semi-prehensile tail?>

  I can list many extant animals that are exclusively arboreal (with an 
exception on the sloth, who can swim) who lack a [semi] prehensile tail. 
It is not a neccesary, though often favored by many mammals, as monkeys 
and pangolins, and even chameleons.

<The more parts of you that are anchored the less chances that you'll 
fall right?>

  Yes. One reason birds have a reversed hallux.

<As for flying, wouldn't a smaller tail be better? It seems that all of 
the major flying animals were adopting a trend towards smaller and 
nonexistent tails. Dromies and Oviraptors had long tails. So did 
Herrerasaurs.>

  Oviraptors did not have long tails. They had quite short tails, as did 
some of the larger ornithomimids (slightly longer relative to body size, 
but comparatively short nonetheless). Also, therizinosaurs. One thing 
these fellows have in common is their long necks (though one genus of 
oviraptor may not have had such a long neck); this means, balance is 
offset to the fore when doing any kind of locomotion, and the normal 
stance of tilting upwards would have actually been prefered during 
locomotion, especially running, as is demonstrated by Greg Paul's 
composite therizinosaur in _the Complete Dinosaur_.

  On the aside, birds have short tails because they no longer needed 
them, as the tail no longer anchors the _femorocaudalis_ muscle. The 
tail is now redundant. Solution? Get rid of the tail. But I'm repeating 
what's been said on this list (and is in the Archives).

Jaime A. Headden

Archosaur J


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