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Re: sauropod adaptations



Dear Demetrios, Happy New Year to you too! In respect
to your suggestion regarding upright rearing among
sauropods being limited to juveniles, one has to
remember that their necks and tails became
proportionately longer as they became adults. If there
was any tendency towards a selection for reduced
rearing or non-rearing as an adult, I don't think
you'd see the kind of onogenetic change I just
mentioned; there was clearly a reason for maintaining
and increasing those long neck dimensions into
adulthood, which I think are best explained as an
adaptation for arboreal conifer feeding. With the
tails I don't currently have an opinion on the
whiplash defense idea, but here again longer length
would have conferred greater range and power to the
tail when used as a defensive weapon against
theropods; like the neck, a reason for greater length
in adults. In the case of juvenile sauropods, I think
that they faced a lot of competition from other,
lower-canopy feeding dinosaurs (like stegosaurs)as
well as each other. As in the post-hatchling phase,
this was probably an extremely critical period for a
young sauropod; like some of today's modern
herbivorous iguanodon species, they may have aquired
the gut-fermentation flora they needed by eating the
adult's dung that fell to the ground. --Mark Hallett  


M. Vital" <vita0015@umn.edu> wrote:
> Dear List,
> 
> In thinking about sauropod adaptations, especially
> concerning necks, tails,
> and juvenile behavior, I had an idea that I haven't
> yet heard or read.
> 
> What if sauropods could raise their necks, and whip
> their tails, but did so
> not as adults, when blood pressure and tail bone
> breaking became a problem,
> but rather as juveniles, when bone is softer, blood
> pressure lower, and
> foliage more out of reach.  I can imagine (yes,
> imagine: pure speculation)
> a young, 20 foot sauropod facing off against a
> predator and rearing up,
> using its claws (if its not a titanosaur) as
> defense, along with a whip
> from its tail.
> 
> What if all those ostensible adaptations for
> sauropod rearing were
> adaptations for sauropod rearing, only not as
> adults?
> 
> I don't know if this is testable, but I thought it
> worth propounding.
> 
> Happy winter, everyone.
> 
> - Demetrios Vital
> 


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