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Re: [dinosaur] Dinosauria reclassification joins Ornithischia and Theropoda in Ornithoscelida




> On Mar 25, 2017, at 10:19 AM, David Marjanovic <david.marjanovic@gmx.at> 
> wrote:
> 
> Gesendet: Freitag, 24. März 2017 um 07:50 Uhr
> Von: "Mike Habib" <biologyinmotion@gmail.com>
> 
>> it may be worth considering if the supinated forelimb anatomy in dinosaurs 
>> was mostly a side effect of the specific pathway they took for forelimb 
>> reduction.
> 
> To have the forelimbs locked in a supinated position is plesiomorphic. 
> Crocodiles have this condition, *Acanthostega* has it. It is actually hard to 
> get rid of while staying quadrupedal. Its persistence in theropods certainly 
> rules out certain hypotheses on what theropod forelimbs were used for before 
> flying became fashionable, but it doesn't itself require an explanation.

That's a darn good point. Fair enough - then I suppose the pathway to reduction 
merely *maintained* the supinated condition, which means far less. No 
explanation needed, after all. 

Cheers,

--Mike

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