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





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> Date: Sat, 12 Nov 2011 11:14:10 +1100
> From: tijawi@gmail.com
> To: dinosaur@usc.edu
> Subject: Re: Perching, climbing, roosting was Re: 11th specimen of 
> Archaeopteryx
>
> Robert Schenck <schenck.rob@gmail.com> wrote:
>
> > I like to keep the goats-in-trees image in mind, because it reminds us
> > that animals don't allways do what we say they're 'allowed' to do, and
> > because, no matter how many goats we see in trees, they're still NOT
> > arboreally adapted. You'd be a crazy person to look at a goat fossil
> > and say, 'yep, foraged in trees'. You'd be /correct/, but still crazy.
 
> I really wish you *wouldn't* keep the "goats-in-trees" image in mind
> when you think about dinosaurs. Goats are well adapted for climbing
> trees. We've been over this umpteen times. Their tree-climbing
> abilities are an extension of their highly refined rock-climbing
> abilities, which entails gaining purchase on narrow and uneven
> substrates.
 
 Really?  What part of a goat is adapted for gripping branches?
 
> So knowing this, you wouldn't have to be a crazy person to look at a
> goat fossil and say, "Yep, foraged in trees".
 
http://2.bp.blogspot.com/_GhcCFcMfw-k/TSn5c-4PetI/AAAAAAAAARA/1noTX2bLcMk/s1600/goatskeleton.gif
 
I don't think we could look at it and say "definately a mammal, so therefore it 
could climb trees with ease."
 
 
 
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> Date: Fri, 11 Nov 2011 06:47:26 -0800
> From: keesey@gmail.com
> To: dinosaur@usc.edu
> Subject: Re: Perching, climbing, roosting was Re: 11th specimen of 
> Archaeopteryx
>
> On Thu, Nov 10, 2011 at 11:12 PM, Anthony Docimo <keenir@hotmail.com> wrote:
> >
> > We *know* a transition occurred - we have birds these days, after all. It 
> > *is* possible. *Nobody* said it was easy.
> >
> > But some people are saying its impossible.
>
> It's perfectly legitimate to question *when* the transition occurred.
 
*nods agreement*

> It clearly happened by the ancestor of Ornithothoraces, but it doesn't
> appear to stretch back to the ancestor of Eumaniraptora.
 
I'm not arguing any of that.
 
All I'm arguing is the claim some seem to espouse, that the transition was 
impossible.
 
 

> Date: Sat, 12 Nov 2011 11:28:56 +1100
> From: tijawi@gmail.com
> To: dinosaur@usc.edu
> Subject: Re: Perching, climbing, roosting was Re: 11th specimen of 
> Archaeopteryx
> 
> Anthony Docimo <keenir@hotmail.com> wrote:
> 
> 
> > clearly the argument seems to be becoming more and more that birds are no 
> > more dinosaurs than mammals are reptiles
> 
> Mammals aren't reptiles. Never have been.
 
 as long as the word exists, people will use it.  best you get used to it.  
(and I know you know what I meant by "reptiles" in the first place)
 
 
> > - the anatomy is so radically overhauled that we can't say the 
> > non-mammalian reptiles are at all like mammals, any more than we can
> > say non-avian theropods are at all like avian theropods.
 
> I'm not sure what you're getting at here. What I would say is that
> the range of motion that theropod limbs are capable of his highly
> constrained. These constraints limit the ability to climb or clamber
> over uneven or elevated substrates, such as trees. These same
> constraints do not apply to anurans, lepidosaurs, or small mammals.
 
 So in other words, "no theropod could ever be in a tree.  ever.  full stop."
 
 so what do you think birds are?
 
 heck, I'm sure the mammals (Mammalia) have overcome constraints of their own - 
constraints that surely separate them from their ancestral clades.
 
 
> > use of branches? paleontologists can't agree on if T.rex prefered live or 
> > dead prey - and that leaves evidence (teeth, teeth marks) :)
> 
> With one notable exception, I don't think paleontologists really
> believe that _T. rex_ was an obligate scavenger.
 
I concede that.  (though I said "prefer" and not "was restricted to")
 
 
> > the sort of evidence you're asking for, would be a mummified tree branch 
> > with protobird clawprints on it. (and then someone would
> > say "those marks are from after the branch fell")
> 
> No, the sort of evidence I'm asking for is arboreal adaptations in the
> manus or pes for branch-grasping.
 
and when adaptations are suggested, you dismiss them.