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

[Dann Pigdon <dannj@alphalink.com.au>]

wa105@mead.anglia.ac.uk wrote:
> 
> Dann wrote:
> 
> >                                          ... I can't see that the
> >increase in protective properties of torosaurus frills would have been
> >worth the inconvenience of such a large encumberance if it were for
> >protection alone.
> 
> But in Torosaurus's case, the extended frill would have pushed the head's
> centre of gravity back.  Just like Pteranodon's crest.  This would surely
> enable the head to be moved faster with the same neck muscles.  Perhaps
> the incresed area of attachment for neck muscles (as well as jaw muscles)
> was a reason for the early frills, but I'm sure the bigger ones were gross
> overkill in this respect.
> 
>                                                                 Bill

        An interesting point, although the problem with many of
the counter-balancing crest theories is that you often get closely
related species with much smaller crests. The crest of Pteranodon
sternbergi is much larger than P.ingens, and the closely related
Nyctosaurus has barely a crest to speak of. The much larger
Quezelcoatlus has an even smaller crest.
        I would argue that styracosaurus had a much heavier
and more cumbersome frill in life than its female counterparts.
Similarly, is there enough difference between the front ends of the
skulls of torosaurus and triceratops to suggest that torosaurus
needed the counter-balance? With such cases of overkill it would
seem that display formed a significant part of the function of the
frills.
-- 
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        Dann Pigdon
        Melbourne, Australia

        Dinosaur Reconstructions:
        http://www.geocities.com/capecanaveral/4459/
        The Australian mirror site:
        http://www.alphalink.com.au/~dannj
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