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Re: Bird vs. theropod dinosaur tracks/trackways



>> 
>> >> 2). What skeletal or other morphological feature(s) cause a bird
>> to walk
>> >>pigeon-toed and theropods not?
>> 
>> >>the pelvis?
>> 
>> Flying birds also have a much larger breastplate to support the
>> muscles needed to sustain flight, thereby widening the body.
>> 
>> _______________________________________________________________
>
>       But where does this leave birds like lesser mynahs and robins
>and so many of the shorebirds who walk quite straight?
>
>       Blue

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Good return. Guess I shoulda said "Most birds..." 
I can't give an accurate answer seeing as how I haven't any, or much, 
anatomical info on birds (quess I should seeing as how I have this 
thing for dinosuars, particularly theropods).  My best guess is that 
for some reason they took a different evolutionary road.    I'm 
working from memory of various Wild Discovery episodes here, but the 
legs of pigeons, eagles, and other birds associated with pigeon toed 
feet, are short and stubby, but more musculure than those of robins, 
and particularly shorebirds.  Robins, mynahs, and most shorebirds 
have thinner, less musculure, and longer legs than their pigeon toed 
cousins.  And theropods had long legs.  
And that's where I get stuck.  Muscle scars on T.rex femurs indicate 
heavy muscle mass.  Perhaps for some reason there was a split, one 
group of birds gets the long legs, and another gets the strong ones. 

Someone help me out, I'm dying here.  :)

Jason 

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