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





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> Date: Fri, 11 Nov 2011 18:33:42 +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:
>
>
> > So dinosaurs require special pleading?
>
>
> Now that you mention it, yes. Yes they do require special pleading.
> Simply invoking snakes and frogs and possums, and how easy these
> critters can switch between a terrestrial and lifestyle, and then
> saying dinosaurs could do it too... it just doesn't mesh with the
> anatomy of non-avian theropods.
>
>
>
> > 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.
>
>
> I'm saying where's the evidence that non-avian theropods could perch
> or roost in trees?
 
 avian theropods evolved from non-avian theropods.
 
 to say that non-avian theropods couldn't do these things and their anatomy 
would never measure up, but the avian theropods can do those things and their 
anatomy always measures up, kinda negates any claim that we need to ditch 
Linnean taxonomy on the grounds that birds are a branch of dinosaurs.
 
clearly the argument seems to be becoming more and more that birds are no more 
dinosaurs than mammals are reptiles - 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.
 
 *that* is how your argument is starting to sound.
 
 
> No matter how intuitively attractive the idea is,
> it needs supporting evidence.

> > and I was pointing out the broad diversity of branch location - not that 
> > protobirds always used all branches

> Where's the evidence that basal paravians used ANY branches?
 
 use of branches?  paleontologists can't agree on if T.rex prefered live or 
dead prey - and that leaves evidence (teeth, teeth marks)   :)
 
 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")
 
> The
> anatomical evidence indicates that confuciusornithids, sapeornithids,
> many enantiornitheans, and some basal euornitheans could perch on
> branches. But no theropod outside the clade formed by these taxa
> shows any evidence of perching. 
 
> > seriously, it doesn't matter what the backbone or shoulder looks like. no 
> > part of mammal anatomy lets you ignore the laws of physics
> > and plant biology (namely that the crown is always above any trunk, so you 
> > always have to cross the trunk if you're crawling from the
> > ground to the crown - it doesn't matter what part of Kingdom Animalia you 
> > are)
 
> Therian skeletons are ancestrally adapted for both scansoriality and
> arboreality. They could climb trunks as well as they negotiaed
> branches.
 
 actually, I thought of one exception to what I said before - the kangaroos who 
can leap 20 feet vertically, they can go from the ground to crown without 
touching the trunk.  but my statement holds true for everything else.
 
> "Kingdom Animalia"??!! Where are you writing from - the 1980's?
 
 I'm writing from the land of "need to make sure he understands what I'm saying 
about no animal of any type - backboned or not - being able to climb from the 
ground to the crown without touching the trunk."