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Re: Cursorial adaptations (was T.rex and elephants)



Gigi Babcock or Ralph Miller III wrote:
> 
> 
> To put it in the form of a simple analogy, which is faster, a racehorse or
> a plowhorse?  Is not the greyhound -- a very fast dog -- also very gracile?
>  Contrast the body type of an olympic weightlifter (built for power)
> against the body type of an olympic sprinter.  You get the idea.
> 
> Ralph Miller III <gbabcock@best.com>

        But surely these are all examples at a reasonably small scale.
Do the same rules apply when you scale things up? Which is the fastest,
a giraffe or a rhino? Giraffes have hyper-elongated legs which,
appart from being useful in feeding, are quite a hinderance. They can
barely reach the ground to drink, and their slow loping run seems
slower than the top speed of a rhino, which has much more robust
looking limbs. I remember reading somewhere that the rhino body plan
is essentially what you would get if you scaled up an antelope to
several tonnes.
        To use this analogy, a hadrosaur looks, to me at least, like
a scaled up version of a hypsilophodontid. Are there any recent
speed estimates for adult hadrosaurs?, or are the estimates for any
large extinct creatures plagued by the fact that we have no living
experience of their biology (and hence the various estimates for
tyrannosaur speeds over the years).
-- 
____________________________________________________
        Dann Pigdon
        Melbourne, Australia

        http://www.geocities.com/capecanaveral/4459/
        http://www.alphalink.com.au/~dannj
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